Timing And Carb Tuning

The objective is to establish the minimum timing and the maximum timing of an engine. Tuning Technical Information from NOS. you can speed up carb to adjust timing by using the idle speed screw. MRC Tuning, Banbury, United Kingdom. The vacuum secondary carb's fuel calibration is usually more efficient as well. One of the major problems in getting your performance engine to idle is lack of idle timing. Photographs by Moore Good Ink: Download text and hi-res images here. We also provide Custom Dyno Tuning, Flashing and Chipping for nearly all makes and models of vehicles. Changed the spacer that was a phenolic unit on the cast ford intake. Let the bike idle for no more than 5 minutes. 4 is around 9. Cylinder Pressures 1-4 90, 90, 85, 105 psi respectively (Surely this level should be higher?) Rolling road test = 79BHP! Very poor! Points 1-3 are being rectified but I was wondering if there is any tuning I can carry out in order to improve our power. If the jet and carb are clear (not likely) the next thing is poor fuel flow from the petcock followed by weak ignition or battery then a timing belt one tooth off followed by poor compression. I’ve followed your work for a while and I really appreciate how you remain so open minded and non-dogmatic. Centrifugal Timing Advance. This is the best method to set timing and tune the carb. You may also override timing options in Configuration_adv. I like that metal spacer with PCV pipe. How to Carb Cycle for Fat Loss. Degrees of initial timing ? at what RPM in neutral, Drive ?? this engine is advertised at 7. Carb Tuning Guide - Free download as PDF File (. It is recommended to check that there is no obvious underfitting or overfitting before tuning any other parameters. SU Carb History SU Books available "Tuning" and adjusting SUs: Mixture adjustment Link to separate SW-EM Tech Article: SU Jet Bearing and Supply Tube Notes Damping of Dashpot Unisyncremoved from its resting place in the toolbox for the first time in more than a decade for dusting and pictures!. This assures that the engine goes through the proper break-in period. running competitors carb with C/S mechanical pump plenty of fuel psi typically 7 psi. On the intake manifold there is a 1/4" NPT port right above the carburetor. For more details on how to get your tuned file or become and official Microchips Tuning dealer, send us an email at [email protected] William then takes this finished machine on its maiden voyage with his son Hans and then returns for its 600 mile service and valve adjustment. In a stock or mildly modified street machine, the distributor vacuum advance senses when you open the throttle and then provides additional timing advance that is required. Different motor will have different induction time, and therefore require different timing. Ignition Timing and Spark Strength Improvement by CDI. Even then, perfection is most often fleetingly confined to a narrow portion of the throttle curve, while the remainder is 'good enough', but not perfect. As soon as the weather changes, track condition changes, or other changes are made (like valvetrain lash, spark timing, etc. The motorcycle has a generator unit that takes the place of typical ignition timing, limiting a tuneup to carburetor settings and sensor maintenance. While there seems to be an Carb gaskets - Confirm that these gaskets have a soft drying sealer (like Gaskacinch or Permatex Hi-Tack or 3Bond However having dual carbs is not necessarily the passport to big time horsepower. Tuning Box : Performance chip tuning for diesel, petrol, hybrid & electric engine | Upgrade your engine power & torque. not to mention carb tuning also becomes mandatory and. Weber DGV (32/36) Holley 5200/G180 is a licensed copy. This method is inferior to tuning with a dynomometer since it often leads to ignition timing which is excessively advanced particularly on. Engine warmed up, but switched off. running E85 on sbf and having issues. It is recommended to check that there is no obvious underfitting or overfitting before tuning any other parameters. In one sentence he says The Excise Duty on all vehicles had gone up by between Rs. Your results may vary depending upon compression ratio and the sophistication of the ignition system. Once the static ignition setting and the ignition advancing mechanism in the distributor is correct, the air-fuel mixture can be tuned for full power and fuel efficiency. Keihin Carb Tuning Manual. Equipment to access and tune your vehicles computer directly - custom tuning for more radical modifications and needs. Advancing the timing should make the engine more responsive and is the cheapest performance upgrade there is. PSL is a renowned world leader in making finely tuned remapping files using cutting edge software development which makes them pioneers in the industry. Older vehicles that have a distributor ignition system will have the ability to fine-tune ignition timing. The objective is to establish the minimum timing and the maximum timing of an engine. This is used to adjust the fuel feed to the engine. If your engine is running too rough, it's important to adjust the mixture and find the correct idling speed to decrease engine stress, keeping things from. If the hose it left in place, when you pinch the hose, any vacuum in the diaphragm will be trapped and possibly cause an erroneous timing check/adjustment. Our service and sales staff is available to assist you Monday-Friday, 8:30 am-5:30 pm Central Standard Time (CST). Whether you need performance products, full engine tuning, suspension set-up, Dyno services or crash repairs. (G) - All Models, (U) - USA, (A) - Australian Model, (Cal) - Californian Model 1984/1985. Most of the timing table I usually see show only the gaps updated only once per lap. " Eric Liedtke Executive Board Member — Global Brands, adidas. The Race Link Racing System is the newest generation of wireless timing from Brower Timing Systems. Starting from AGESA version "Combo-AM4 0. T but made more power/torque with a richer LAMBDA of 0. you guys are right ,as we all know the later model L76/L77/L98/LS3 etc don't need a lot of timing to make the power/torque that you are after, my L76(exhaust only) only runs 18-19* at W. Other than the flat spot it seems good. Trust us, it is worth every penny for DCOE owners. The Main or High Speed Jet is in the direct center of the carb, the Mid Range jet is offset from the center. Generally, larger venturis admit more air to the engine, but weaken the "signal suction" to the fuel in the emulsion well. The mixture is adjusted with the two screws in the front of the carb base. After some fine-tuning and using less egg yolks, it was. carburetor-body gasket surface. Parts involved: • Idle Speed Screw • Idle Mixture Screw • Pilot Jet (Idle Jet, Slow Jet) Carburetor tuning at idle and low speed is accomplished by adjusting the Idle Mixture Screw, the Pilot (or Idle) Jet, and Idle Speed Screw. turn the key to "ON" and let the carb fill with gas, you can watch the sight glass on the front of the carb. Place carb assembly on its side to remove any pressure from the floats and measure the float height with the floats resting lightly on the float pin so as not to push it in at all, but not rise above it either. Carburetor selection; explores possible alternate choices of Type and size, depending on your engine, displacement, head, intake manifold, cam timing, etc. Right now I am at 20* base, and I idle around 205 - 210 F. spark quality, and timing, carburetor gaskets, and vacuum hoses, the misfire. (or "tune like a star in 4 easy steps!) Carb Kit Design is a combination of science, art, intuition and and at times, a fair dose of wizardry. A brief definition and the goals of nutrient timing. However, as with all mechanical devices, carburetors will wear over time and will also require. *Note: In FM7, torque is no longer listed in the Upgrades interface, but it can be found in the "My Garage" and "Select Car" interfaces. Tuned file is received back within the hour. If you don't have the right size carburetor it can cause a series of problems from the second you try and start tuning. 157FMI 125cc OHV Single Cylinder with Single Exhaust Port. " Eric Liedtke Executive Board Member — Global Brands, adidas. ADVANCED TUNING: If you want to experiment with the other circuits of the carb (Mid & High), you will need to remove the carb from the engine, drain and remove the fuel bowl and unscrew the jets on the bottom side of the carb. I cant seem to get the bike to even run long enough to warm up. Cars built in the 1970s (at least, after 1972) and 1980s tend to have numerous vacuum hoses, and by the time you get your car, both shadetree and "professional" mechanics have usually left some off and re-routed others. Standard lock-up clutch. There is a timing window in the bellhousing on the passenger side of the motor. when its warmed up, I can rev it up a bit and she'll spit a flame out the exhaust for the rear cylinder which tells me the intermediate. If you've had success losing tons of weight with Primal low-carb eating, but have hit a snag, consider a carb refeed. A lot of times it is caused by the timing being too far advanced. A good place to start for most cars with Webers on pump gas is 12-14 Degrees advance at 1000 RPM idle and 36 Degrees total advance by 3000 RPMThis is not cast in stone and you need to make sure your car does not Detonate at these setting. Better Products in Half the Time. Tuning by color is the more simple way to tune although in many cases, more risky. • If one is installed, the air cleaner is clean. Because of their great performance they come stock on a lot of the. -Carb Mod, jetting -Custom Piston-Set up notes on timing **we offer an HPI ignition box for this as well 2012-19 KTM300SX Stage 1 | $400 The ktm 300 completely transforms when modified-Porting Stage 1-Head Mods-Set up notes for timing and jetting-This package can produce the same HP and front side curve as most 450's with an easily ridden delivery. Ignition Timing While this story will focus mainly on carburetor modifications, a professionally-tuned carburetor won't function well unless the engine at least has a decent initial timing setting. CARB Executive Order Numbers. Choke the carb or prime it, until the carb is wet. This guide to tuning a carburetor will explain how to correctly adjust the gas/air mixture. Advanced timing helps cooling. AdBlue Removal. Giovanni Giarratana / gioracer96. Start set up by confirming carb base line settings. NEW CPU that allows faster data processing. We continue to make payments to support the research programs in our portfolio, and will announce new awards as they are approved and contracts finalized. Rebuilding Fuel Systems. Most Critical! Be sure for initial carburetor set up all air by-pass screws should be in closed position. Over time they become hard, brittle and cracked and suffer from dry rot due to excessive. The air screw is located to the left side of the mouth of the carb, and the. Quora is a place to gain and share knowledge. Jump to Latest Follow 1 - 20 of 25 Posts. JEGS has the carb tuning components you need to get the performance you want from your carburetor. Tune your Yamaha PW50 for peak performance and head for the track or the trail. Tuning for Mileage Now we get into aspects of carburetor performance which are transient or harder to quantify. Vacuum readings in drive to determine correct power valve or brake issues. you can speed up carb to adjust timing by using the idle speed screw. For tuning procedures we have a number of manuals available to the left. Decreasing the timing advance raises low-end power, reducing the high-end. Can anyone give me some pointers on tuning. PERFORMANCE TUNING. Demon's carburetor selection guide consists of helpful recommendations on ignition timing settings with consideration to things such as camshaft duration, valve lift, and other contributing factors to assist in the timing process. Our online registration site is owned in-house and can service all levels of Cross Country and Track & Field meets. How to go about replenishing your muscles energy stores, reduce muscle breakdown and build muscle. We move away from the known setting of Wide Open Throttle to gas mileage and "throttle response". befor trying another stage. 2 Stroke Carb Tuning For Customers Who Purchase Our Carburetors We have available a 10 Jet JetKit. It's kind of like nature's water injection; since. Holley does a pretty decent job of supplying a. Some maintenance tasks go beyond the basic, though, and the day may come that every lawn tool with a gasoline-powered engine will need to have the carburetor adjusted or cleaned. My Guide to Carburetor Tuning. Diamond Tuning is the family operated company, so we carefully select the staff to our garage. ECS Tuning began developing new parts in 1995 with an Audi S4 Big Brake Kit that gained popularity on the early Audi forums. When setting the timing for your 914 with carbs, after following all of the advice above, such as setting the dwell angle, you will need to know where to set the timing and at what RPM. The term carb cycling encompasses various strategies in which you rotate periods of higher- and lower-carb eating. CB450 tuning I am currently rebuiding the engine on my 1966 cb450 black bomber and I have some questions being my first time ever rebuilding an engine. On conventional carburetors the throttle cable is connected directly to the throttle slide. Three screws on the carburetor are used to fine tune the engine to ensure smooth operation. There are some basics we can share. Does ignition timing directly affect the idle air/fuel mixture? I set the timing (by ear) on my '71 440. Are You Ready to Tune? I have some basics and. Now that we have selected the right carburetor, we can dig into tuning it. Centrifugal Timing Advance. you will prob want your initial timing up closer to 18 or 20 (depending on compression ratio and how good the gas you are using) and a total of about 28. World's only AMG derived Mercedes Benz Tuning and Performance Parts since 1989- Buy Online. preferably 93 octane if you have access to it. Two of the primary reasons why it is recommended to consume high glycemic carbohydrates around your workout. The optimum setting for the Edelbrock carburetor is to run between 550 and 650 rpm. Centrifugal Timing Advance. Timing and Choosing Your Carbohydrates 3-4 hours before training. COM 2-Stroke GP Motorcycle Racing Message Boards (for Honda RS & Yamaha TZ). Think about it. Carb timing refers to when you eat your carbs. Conversely, if you set the points correctly at every tune-up you will find that the timing never changes! Step 6 — Set the timing by connecting the light (inductive or direct) and then mark the correct timing position on the crank pulley or damper. To tune a carb, one simply replaces a jet with a larger (richer) or smaller (leaner) jet, turns a screw either in or out, substitutes. onece the carb has gas pump the throttle a few times and start the car. If you are back firing through the carb, then you need to retard the timing a lot. The "H" screw is used for adjusting the saw’s RPMs when at high throttle, while the "L". 5 Light Acceleration: 11-12 Anything over medium acceleration: Maxed out rich (gauge reads as low as 10) It ran perfectly on the primary circuit, but getting into the secondary side too early. Before attempting to adjust the carbs, the engine must have correct cam and ignition timing along with a careful valve adjustment. Learn more. Software available for modifications. I’ve followed your work for a while and I really appreciate how you remain so open minded and non-dogmatic. Effect: After a long ordeal of tuning and timing adjustment I gained significant mid to upper power. Timing Solution software is designed to forecast stock market future moves, to help you make better trading decisions. The IDA carbs have no Air Bleed Hole but do have an F number to identify this feature. Dyno tests have shown increases of 1/4hp! This is especially true in the upper RPM range where the power just keeps on pulling. We are standing by to take your product literature requests, dealer inquires, or refer you. Oversized carbs need a intake manifold with a minimum ID of at least that of the ID of the exit of the carb. 25-1 comp,comp magnum 294s cam,. There is no dyno that "tells" one how to assemble or modify the carb to deliver proper power and response. One of the major problems in getting your performance engine to idle is lack of idle timing. Why ethanol is bad for 2 strokes. com is your source for PC car tuning, car computer chips, engine monitors and mileage programmers by Granatelli, Banks, Bully Dog, AEM, Hypertech, Jet Performance, Painless, Diablosport, Predator, SCT, Superchips & Edge. Set the initial timing at 5 +/- 2 degrees BTDC and tighten the distributor hold down bolt so that the distributor housing will not rotate. Do not depend on the factory delivered settings. tuning guide!I appreciate it! faigolfgti, May 16, 2006 #5. These basics should significantly improve the tuning you do throughout the weekend so your jetting is perfect for the main event. Let's set the top end first since it's the easier of the two. Real-time Live Timing and an accurate Race Tracker enable you follow every race. You can't tune a carb with the same accuracy as EFI over as many conditions as you. Yeah, right! There are quite literally millions and millions of jet combinations. Valve spring seat pressure: KZ / Z1 / GPZ - 100lb. Along with performance Holley ® modified carburetors, BLP Billet Xtreme carburetors, gaskets, belt driven fuel pumps, fuel logs and regulators. Carburetor "tuning" is a very complex subject. Having the correctly-sized carburetor will make the tuning process much easier. The possibility that the 4. Knowledge is power and whether you are tuning your car yourself, wanting to start a career as a professional tuner or even if. 1- Idle Speed Screw 2- Idle Mixture Screw 3- Accelerator Pump Turn screw counter-clockwise 1/4 or of a turn at a time, until engine. Oversized carbs need a intake manifold with a minimum ID of at least that of the ID of the exit of the carb. Some vehicles feature a timing chain instead of a timing belt. Software available for modifications. lunati 61605 240/249 carb, 1. So after a re/re of the intake on my 289 I had a suspected vacuum leak. Most importantly, you can only expect 5. Boom - problem solved. Fairly in depth timing curve questions - Carb induction If this is your first visit, be sure to check out the FAQ by clicking the link above. A particular sore point is the fit of the throttle slides; a poor idle is often traced to a worn slide-to-carb body fit, with the diagnosis made in the time-honored way by simply pushing in. Why is fine-tuning key? Because if you have big datasets, and you run a naive grid search on 5 different parameters and having for each of them 5 possible values, then you'll have 5⁵ =3,125 iterations to go. Adjust the top end needle for peak RPM. condition page: some information about the condition like oil quality. Note; The methods used to arrive at a good carb tune may be useful for others to follow, but the actual settings will vary with atmospheric and engine combination. FiTech Go EFI 4 600 hp self-tuning fuel injection systems have the ECU mounted on the throttle body for greater self-containment, clean installation, and easy setup. JEGS has Quadrajet/ Q-Jet tuning parts as well as Edelbrock tuning parts and carburetor parts for Barry Grant, Holley, Quick Fuel and other carburetor manufacturers. This is a street car, so since I don't really care what my A/F ratio is outside of that range, a narrowband is fine for me. Motor timing depends on induction a lot, and induction also depends on many factors such as the loads (current), coil resistance, coil number of turns and so on. [email protected] 1585lbs 35 nozzels,70 main,36* timing Engine 2-572 bbc/gide dragster best et 7. Sooooo last week I did my motorbike carb conversion. But by the time you added up all the parts, including an automotive Weber carb, it was going to be Then clean it up, sell it and buy a sportster that already has a carb and never needs the valves Unless you're really good at tuning bikes, have the equipment and lots of time, I wouldn't mess with it. A vacuum gauge can tell as much about the internal and external workings of an engine as the combination of a voltmeter, compression gauge, stethoscope and timing light. Using an air-fuel meter is the preferred way to tune, but the EPS carbs can also be successfully tuned with just conventional tools. RM125 Kick starter drive gear : Bulletins 18 - 26: 18. ADVANCED TUNING: If you want to experiment with the other circuits of the carb (Mid & High), you will need to remove the carb from the engine, drain and remove the fuel bowl and unscrew the jets on the bottom side of the carb. There is a large amount of horsepower to be found in a properly tuned Once you remove the cap and spring you will see the slide inside the carb. Zero-maintenance 3BOS4U1 electronic ignition means you won't have to fool with points and timing again – always stays in perfect tune! Our SVDA distributor is a quality reproduction of the original, vacuum-advance Bosch 0 231 170 034 / VW 043-905-205, federal model distributor that came stock from the factory on the 1974 VW Beetle with 1600. Older vehicles that have a distributor ignition system will have the ability to fine-tune ignition timing. (The pointer on the timing chain cover will be lined up with the timing mark on the pulley) 3. The concept is simple: a spark-plug-sized sensor mounts in the exhaust stream, and generates an output voltage in proportion to the air/fuel ratio. At HD Tuning we do not just change ignition timing and air fuel ratios, we go much deeper in the file to find hidden power in the form of "torque limits. And solved within about 40 minutes so pretty darn good. Have you read the weber tuning information on the racetep. I have read 16 and 14 BTC but the car seems to like 12 better. - A1-A7 Specs extracted from the GPz900R Workshop Manual, - A8 Specs from the Kawasaki Dealer- microfiche. The other is engine timing! IF your timing is too low it will make the carb appear out of tune! This is often over-looked and will cause you to tinker with the carb and you'll never get it running right. timing actually work. Also, whenever a carburetor spacer is added or deleted, or a camshaft, cylinder head or intake manifold change is made, it will be necessary to retune the carburetor for maximum performance. The original carburetor was a good experiment on. When less power is drawn from the battery, you can expect lower overall temperatures and longer run times. Yes, the included CARB tune is a locked tune, that's the whole point and the only way it is CARB legal. 95), this book has some good general information that applies to Keihin as well as Mikuni products. The following pages supply enough information to make such alterations relatively simple. Car parts for modern & classic cars. I found a small vacuum leak in the intake from the airbox into the carb and tightened that clamp. This carburetor requires excessive initial ignition timing advance to avoid stumble on take off (if the ignition timing was retarded, we would have to open the primary throttle plate to obtain the necessary idle; this would expose the progression bleed holes which in turn would require that the idle mixture be leaned to compensate for this. It also means that many of those tuners out there in the industry right now don’t have a proper understanding of what they’re doing and the results are predictable - Poor engine performance, terrible driveability, and of course, needlessly damaged engines. The term carb cycling encompasses various strategies in which you rotate periods of higher- and lower-carb eating. AdBlue Removal. Weak vacuum do to leaky valves or wrong cam timing can cause weak fuel delivery from the pilot circuit. When you initially set up the carburetor for methanol err on the side of rich. Timing and synchronization on an outboard engine is extremely important to obtain maximum efficiency. Site tuning studio TopCar - tunings Porsche Cayenne (TopCar GT (958. The Android app can be downloaded here. ~~~ Note: Before we begin to adjust the carburetor, the valves, points, and timing should be set. Adjust the carb slide stop screw till the engine has a slightly high idle speed. As of press time, thirteen other states have since adopted certain California standards: Arizona From that point, CARB may apply a "grandfathering" process. 90 and was a daily driver. A saw with a properly adjusted carburetor will produce maximum power, minimal smoke, run and idle smoothly, and give trouble free service. You can find an extensive range of Honda parts from well-known brands in our online store, such as: We offer all products at very low prices, often. Timing should not have a large effect on how smooth the engine idles, that is more dependent on how the carb and ignition are tuned. With volume control screw you tighten it for a. Whether you need performance products, full engine tuning, suspension set-up, Dyno services or crash repairs. However, there are several other methods available that allow us to access the Electrically. A saw that is too rich will produce excessive smoke and have. After warming up, I played with the air screws to maximize the rpm. After initially setting float levels and idle screws (highest vacuum at 1/2 turn from bottom) my AFR's were: Idle: 13. Carb timing refers to when you eat your carbs. you guys are right ,as we all know the later model L76/L77/L98/LS3 etc don't need a lot of timing to make the power/torque that you are after, my L76(exhaust only) only runs 18-19* at W. Plug the gauge into the intake manifold on a warmed-up engine with the distributor loose enough to rotate. VAT) Read more; CARBURETTOR AIRFLOW METER. BTDC 2)Points to. Trouble shooting the ignition system. Along with performance Holley ® modified carburetors, BLP Billet Xtreme carburetors, gaskets, belt driven fuel pumps, fuel logs and regulators. Engine 1-434 sbc/glide dragster best et 7. A saw with a properly adjusted carburetor will produce maximum power, minimal smoke, run and idle smoothly, and give trouble free service. for coil just get a blue coil or msd blaster type. Sealing engine-related vacuum leaks isn’t just a performance option; It’s a critical requirement for all Classic Opels. Timing is adjusted by opening or closing the gap. Low compression pressure Carburetor Tuning: Typically, mid-range performance is controlled by the jet needle/needle jet combination. Beginner The Ultimate Upper-Body Exercises and Workout Fine-Tune Your Chest Workout Plan The Ultimate Functional Fitness Workout Program All. Carb companies have continued to refine their system of fuel delivery and in many cases modern carburetors can even make more power than alternative systems without all the complicated sensors, computers and electrical wiring. Changed the spacer that was a phenolic unit on the cast ford intake. (victor jr intake is under $250, and can match/outflow almost any efi intake, dont even mention porting it) also, my recommendation for the timing, set it this way. Rode the bike a few miles and readjusted the air. Pay extra attention to the choke cover. In other words a '77 Bronco engine is a '70s Mustang engine. Site tuning studio TopCar - tunings Porsche Cayenne (TopCar GT (958. Upgrading your air intake system, installing an aftermarket exhaust and tuning with a power programmer all have the ability to boost your At the same time, they've been busy confusing performance enthusiasts. not to mention carb tuning also becomes mandatory and. Vacuum readings in drive to determine correct power valve or brake issues. Tuning Box : Performance chip tuning for diesel, petrol, hybrid & electric engine | Upgrade your engine power & torque. Most of the timing table I usually see show only the gaps updated only once per lap. Whether it is a stock or aftermarket carburetor, you will need to consider the temperature, altitude and humidity as these can have an effect on how well it is set up. This data comes from my jetting PILOT JET + AIR SCREW- they control the engine at closed throttle. The carburetor in some of these photos is not correct for the car and has been replaced by a NOS Holley 1945. 1), TopCar GT (958. after a full tune up i cut slots above and below the baffle and drilled 5 holes in the baffle to open the muffler way up. High-quality wiring harness w/ mesh loom & wide-band o2 has fewest connection wires in market. the ike doesnt back fire anymore. VW engines are notoriously under carbureted by nature of the original design. Assuming your carb is properly jetted. Carb Info and Specs for GPz900R Range (1984 to 1991). The bike was running pretty darn good, but it would carb fart regularly, have poor response if I blipped the throttle so I decided to try to fix it. Tuning the static or initial timing is achieved by simply twisting the distributor body in relation to the rotor. The Air Bleed for the IDA carb is in the Idle Jet holder and it is metered similar to the DCOE. To check, disconnect the vacuum retard hose (attached to the front of the vacuum chamber and rear of the carburetor) with the engine idling. 80% or more of tech calls we receive on carburetor issues usually are cured by setting the timing events correctly and upgrading the ignition system to handle the engine and today's fuel formulations. Don't forget that the ignition timing curve takes a sharp dive to 20° after TDC, at around 12,500 RPM and acceleration from then on only get slower. Now that you know where the "F" mark is located when the static timing light initially turns on, you will need to align the "F" with the index mark, so you can either ADVANCE or RETARD the contact breaker points plate. Now, let’s tune your saw. Audi, Porsche, VW & Seat Tuning Specialist. All divisions Tuning Performance Cars Motorsport eMobility Unternehmen. 50-State Legal Tuning Products. 3) Tasso SAS Blank. NEW CPU that allows faster data processing. Back in the day when carburetors were all we had, engine modifications would be "tuned" by carb jetting and distributor adjustments for peak torque and With the introduction of the first generation of ECUs, we were given the ability to adjust fueling and ignition timing maps for optimal efficiency at. After warming up, I played with the air screws to maximize the rpm. How To Do A Complete Engine Tune-Up Part II by Skip Burns. Set the low end & high end needles to about 1 to 1 1/2 turns each. 6 scorpion roller rockers eddy 95cc heads, 10. Tune-Up Specifications - Massey-Ferguson & Ferguson This data has been gathered from old out-of-print material. If your car features vacuum timing advance in addition to mechanical timing, and you'll need to loosen the distributor adjustment bolt before you start the engine. As an example, a tuning product may How does CARB legalization affect the tuning market? In California and in those states that have adopted. And it wont idle when cold at all. A low motor timing offers the potential for a very efficient power system. If you have a tachometer, great. Check the timing and adjust to manufacturer’s specifications. should get yourself a synching tool to "synch" the carbs. Carburetor Tuning 2. Look in the 4 stroke knowledge base forum for the details. How to go about replenishing your muscles energy stores, reduce muscle breakdown and build muscle. tuninG Guide. This book is mainly aimed at the DRLA carbs but has small sections about the DHLA and FRD carbs as well. You may never make as much power as the top AMA bikes - but you CAN avoid throwing away the power the engine makes-Yamaha TZ250 carb tuning. Engine should be at idle speed. Headquartered in Florida, USA with an authorized dealer network throughout the world, we offer unparalleled performance products for your vehicle. "And remember, where you have a concentration of power in a few hands, all too frequently men with the mentality of gangsters get control. After the basic engine condition and tune-up (fuel pressure, timing curve, etc) is confirmed to be correct, the next step is to determine what the air/fuel mixture is at idle through 3000rpm. Diamond Tuning represents the most of well known brands in tuning industry. I swapped out for a single plane and single. Older vehicles that have a distributor ignition system will have the ability to fine-tune ignition timing. At the mo I think it is still sucking in air as it aint quite running right BUT it runs. Why is fine-tuning key? Because if you have big datasets, and you run a naive grid search on 5 different parameters and having for each of them 5 possible values, then you'll have 5⁵ =3,125 iterations to go. 25 turns out on my 360. The Race Link Racing System is the newest generation of wireless timing from Brower Timing Systems. Controlling the fuel mixture can be done by changing the size of the jet. Idle and cruise settings of the center carburetor SHOULD NOT CHANGE when the end carbs are installed. FiTech Go EFI 4 600 hp self-tuning fuel injection systems have the ECU mounted on the throttle body for greater self-containment, clean installation, and easy setup. Go to full throttle. Dellorto carb tuning on a Moto Guzzi Sport 1100, with some gearing and ignition rambling Something I haven't done for 22 years - played with carb tuning on a Sport 1100. tuned, but its timing and “overlap” with other systems is critical to proper performance. In other words a '77 Bronco engine is a '70s Mustang engine. Set the meter to OHMS, or "resistance" and in the "times" or X 1K ohms range. This data comes from my jetting PILOT JET + AIR SCREW- they control the engine at closed throttle. 2), TopCar GTR (958. Proceed carefully and document the timing change by measurement, either by degrees of crank rotation or by millimeters before top dead center. -Installed 1/2" spacer between manifold and carb (because of fuel boiling off)-Changed out carb metering rods-Set timing to 18 BTDC -Use premium gas The car was knocking under load upon accelerating or going uphill but after playing around with the timing the knock is now gone. https://dd-tuning. Mikuni Carburetor Tuning. IGNITION: Digital ignition, programmed timing curves electronic rev limiter, battery powered ignition CARBURETOR: Dellorto VHSB34 XS, float bowl carb FUEL PUMP: Mikuni DF 44-210, external type, crank case pulse powered FUEL: 93 Octane unleaded PRE-MIX OIL: Rotax XPS MAINTENANCE INTERVAL: top end at 15-20 hours, bottom end at 25-40 hours. Usually this means when during the day, morning versus night, but it can also mean relative to exercise or other activities. 4)set to color tune. We move away from the known setting of Wide Open Throttle to gas mileage and "throttle response". There is a lot of misinformation about ignition timing and cooling. Adjusting Ignition Timing. 595 lift,248 dur @. This is simple, easy to do, and near fool-proof. Comer Carb Tuning. Any time a change is made to the air intake/flow, fuel delivery, and or exhaust rejetting and carb tuning may be in order, usually these are This will help you understand the parts of your carburetors. High RPM engines. 5 - 21mm BTDC • Timing (Degrees) 14 – 17 deg BTDC • Ignition primary coil resistance. Note: An exception to this is the G-23 Glow engine, which uses a different carburetor. A clean Mikuni carburetor with a properly adjuste. The points should just start to open when the mark on the flywheel lines up with the "f" mark. Just change the view (Y on the xb1 controller) to find it. TorqueCars take a look at the power plant of a car, the engine and examine the wide range of engine tuning options availble. 5 turns may be ok. 53,805 likes · 426 talking about this · 1,517 were here. RM125 Kick starter drive gear : Bulletins 18 - 26: 18. Plug the gauge into the intake manifold on a warmed-up engine with the distributor loose enough to rotate. Find FiTech Go EFI 4 600 HP Self-Tuning Fuel Injection Systems 30001 and get Free Shipping on Orders Over $99 at Summit Racing! When it comes to fuel injection versus carburetors, new school is just too cool. So, I pulled the carb to check what you talked about in the first part of your post the T-slot. Our Motocross Carburetors and enginereed to meet the demands of gruelling motocross races. Better Products in Half the Time. 171mm diameter with 6mm centre hole If you want to set up your ignition timing very accurately this is what you will need. Check the timing and adjust to manufacturer’s specifications. just picked up a nice used ms290 saw. No carburetor can be tuned correctly without having the timing events correct and the Ignition system must be adequate for the application and be able to hold the timing events correctly under load. Professional timers, event organisers and those new to timing invariably choose from our Ultra range as well as our ground-breaking new Joey timing system. The is the ultimate hop part for your Comer 50. We offer all around the chip tuning, such as programming devices, components, soldering stations, tuning files, etc. 4 is around 9. also drilled like 6 holes in the deflector to make sure it flowed real good. You will need adjustable cam spockets to achieve this level of cam timing and a piston locking tool. These are not commonly used in standard carburetor adjustment. Equipment to access and tune your vehicles computer directly - custom tuning for more radical modifications and needs. Tuning & Performance Accessories Facebook Instagram. No matter how glamourous the model, we have an experienced team who are committed to improving the performance of your car. A good place to start for most cars with Webers on pump gas is 12-14 Degrees advance at 1000 RPM idle and 36 Degrees total advance by 3000 RPMThis is not cast in stone and you need to make sure your car does not Detonate at these setting. Posted: Tue Oct 19, 2010 4:27 pm Post subject: 1915 engine timing and carb tuning Had a 1600 dp that we built and it had a catastrophic failure due to faulty parts (one of the lifters pretty much disintegrated). CVT Drive Tuning. No starter drag, smooth idle. In one sentence he says The Excise Duty on all vehicles had gone up by between Rs. Trust us, it is worth every penny for DCOE owners. Since carbohydrates have 4 calories per gram, adjusting carbohydrate intake while keeping fat The same principles of good nutrition apply equally to "everyday" eating and carb cycling phases, including proper meal frequency, omega-3 fat intake. I used the articles by Damon on Peformance Tune Your Secondaries , Q-jet Secondaries Part 2 , and Q-jet Idle Problems , to help with the tuning of my Edelbrock #1904 Q-jet. 5 PV's (looks like I need 7. 95), this book has some good general information that applies to Keihin as well as Mikuni products. While taking the appropriate precautions for the safety and well-being of our customers and employees, we are continuing to fulfill all orders and support our customers. To verify compliance information, visit CARB's website by clicking here. And the 165 air bleed could be a little bigger to help with the rich toward the top of the primary. From sports drivers to circuit racers, AKR Performance is the place to go. "And remember, where you have a concentration of power in a few hands, all too frequently men with the mentality of gangsters get control. If your car features vacuum timing advance in addition to mechanical timing, and you'll need to loosen the distributor adjustment bolt before you start the engine. A common carb cycling schedule is eating low-carb for five. For detailed information on overhauling and tuning the Motorcraft 2150 carburetor, check out this page. Of course, if you advance enough to enter pre-ignition or detonation you will start to. You will then automatically participate in our prize draw at the end of the month. It is sometimes, but not always, shortened to carb in North America and the United Kingdom. Tuning for the Weather There are three inexpensive tuning tools and one driving tool you can use to compensate for changes in weather conditions: 1. Being a hands on, self taught 'Carb Tuner', I back up my seat-of-the-pants tuning with dyno runs, charts and proven results. To learn more about our line of performace motocross Keihin PWK carburetors is the dominant carb on the factory motocross machines. World's only AMG derived Mercedes Benz Tuning and Performance Parts since 1989- Buy Online. If One Hour Before Training. The other is engine timing! IF your timing is too low it will make the carb appear out of tune! This is often over-looked and will cause you to tinker with the carb and you'll never get it running right. However, there are several other methods available that allow us to access the Electrically. Carburetor Tuning 2. and so forth) Then set valve lash with warmed engine. No starter drag, smooth idle. With the loose carburetor, cracked distributor cap, and out of adjustment carb, I'd say fix those things and make sure the choke is fully open when warmed up. Decreasing the timing advance raises low-end power, reducing the high-end. Right now I am at 20* base, and I idle around 205 - 210 F. Chiptuning files service: Stage1 Remap, DPF off, EGR off, DTC off, AdBlue/SCR off, lamda off, intake/swirl flaps off, ECU remap, tuning files. Easily Tune Your Throttle Rate to Riding Conditions and Rider Preference. The graph below shows the range of effect of each of the adjustable parts of a carburetor. befor trying another stage. Don't expect your hot small block to idle at 900 with 8 - 10 degrees of initial timing. set idle screw to 1 turn, adjust idle mixture etc. Check … Continue reading →. And from what i have read on this site, a valve adjustment is a frequent occurrence on these bikes. Flatirons Tuning is the performance division of Flatirons Subaru in Boulder, Colorado. It boosts leptin and fat burning. That same carburetor is on my old Chrysler. Account for vacuum timing, if necessary. " Torque limits are how modern ECU's limit power and efficiency. Using a vacuum gauge and dwell meter when adjusting a carb is by far the best way to tune older engines. [email protected] 1625lbs 36 nozzels,54 main,36* timing Engine 2 on gas ran the same numbers,i thought we might. tRFC time in units of ns is the outermost left and right columns. If set too low, the saw will die. This is done on automatic choke carburetors by first. Now your RSCHIP can withstand extreme heat and unexpected electric spikes. JEGS has the carb tuning components you need to get the performance you want from your carburetor. However, there are several other methods available that allow us to access the Electrically. HEI) where timing is set manually. 4 x #135 Main Jets. Older vehicles that have a distributor ignition system will have the ability to fine-tune ignition timing. Make one adjustment only to the first screw. It has the S&S super E carb and intake on it and I think it has thunderhead exhaust on it. This is important, and they should be. ) What carburetor tuning myths do tuners frequently fall victim to?. Also,what is the correct position for the carb needle in a D14?----Im told 2nd notch and then again 3rd notch! Many thanks for any help, Jez. Fine-tuning the carb in this manner will improve part-throttle operation and should eliminate that annoying off-idle stumble. SU Carb History SU Books available "Tuning" and adjusting SUs: Mixture adjustment Link to separate SW-EM Tech Article: SU Jet Bearing and Supply Tube Notes Damping of Dashpot Unisyncremoved from its resting place in the toolbox for the first time in more than a decade for dusting and pictures!. Having the correctly-sized carburetor will make the tuning process much easier. Turkey Keto Stuffed Bell Peppers. Nitrous System Theory, Selection, and Tuning As modern engines become more difficult to modify, the use of nitrous oxide to obtain phenomenal performance gains is on the rise and for good reason. Our online registration site is owned in-house and can service all levels of Cross Country and Track & Field meets. ) What carburetor tuning myths do tuners frequently fall victim to?. Air Fuel ratios can also be optimized on the fly as you drive. 455 olds and edelbrock performer intake and holley 700cfm. They use an oxygen sensor in the exhaust stream that can accurately gauge the air/fuel ratio of the engine at any given time, which allows you much more precise adjustment. One obvious exception is a level control loop, which contains an integrating process. Valve Timing Table The following table contains complete valve timing specifications, valve tappet adjustments for all models of Dodge motor cars from 1925 to 1930 inclusive. Decreasing the timing advance raises low-end power, reducing the high-end. Valve tappet adjustment for all late Dodge models are critical and should be made with engine idling. A low motor timing offers the potential for a very efficient power system. 171mm diameter with 6mm centre hole If you want to set up your ignition timing very accurately this is what you will need. • Factory recommended jets are installed and are not worn or damaged. Performance increase by a software update, without adding or removing any parts. You can unsubscribe or ask us to delete your data at any time. Bottom notch is the richest. thats what i think. Example: Magneto timing was reduced 6 degrees in our blown alcohol drag racer, and our low-end 60-foot times were quicker by 0. There are some basics we can share. Tune your Yamaha PW50 for peak performance and head for the track or the trail. set idle screw to 1 turn, adjust idle mixture etc. Set the timing. We offer the hardware without the locked CARB Terms are 3 years (36 months) or 36,000 miles, whichever occurs first Time is measured from the vehicles original in-service date and the mileage is. This is done on automatic choke carburetors by first. Carb Setting guide, compression, v/v timing. Tech Tip #1 Before you go trying to fix all the errors of the previous carb tuner, set your carb up to the stock Holley spec for your carb List Number (stamped into the front of the air horn). Open the butterflys of the carburetor with the carb and metal spacer lined up together to make sure the butterflies move smoothly without jamming up against the spacer. Whether it is a stock or aftermarket carburetor, you will need to consider the temperature, altitude and humidity as these can have an effect on how well it is set up. Dellorto Dcoe 40s carburettor tuning specialist. Jett Tuning, in Camarillo, CA, is motorcycle performance shop, specializing in DynoJet, performance upgrades, servicing, tires and accessories for race bikes, dirt bikes, street bikes, Harley Davidsons, V-Twins, ATVs, UTVs and Watercraft. Some AMS Performance upgrades may solely be used on vehicles in sanctioned competition which may never be used upon a public road or highway, unless permitted by specific regulatory exemptions (such as a CARB E. AdBlue Removal. 25:1 compression ratio will ultimately dictate the end result. At idle, with the vacuum advance hose disconnected and plugged at he carburetor, this is the timing that you see with the timing light on the timing marks. 80% or more of tech calls we receive on carburetor issues usually are cured by setting the timing events correctly and upgrading the ignition system to handle the engine and today's fuel formulations. Chip Tuning - Eco75. Ignition 5. Contents[show] Terminology Lean: referring to the tuning of a carburetor in which the fuel/air mixture contains too little fuel and too much air Rich: referring to the tuning of a carburetor in which the. T and then my LS1 h+c/manifold etc only runs 21* at W. Sorry for the rambling post, but I just have to vent a little frustration until I can get my hands on the timing light again this week to get the. warm up the engine before adjust the carb. It generally includes swapping carburetor jets and adjusting the distributor to advance or retard spark timing. Harley CV Carburetor reference diagram. In other word it changes the time of the spark that ignites the fuel. condition page: some information about the condition like oil quality. It is sometimes, but not always, shortened to carb in North America and the United Kingdom. I use to run a 355 with 11. BTDC 2)Points to. For its part, tune-up shop Manhart offers us a cheerful Christmas-themed, power-boosted Mini John Cooper Works. We’re just as happy to tune up your carburetor, ignition points, distributor (and cap, rotor, and spark plug wires), timing belt, and fuel filter. Quadrajet, high idle with warm engine Throttle return springs and choke unloader issues. Don't expect your hot small block to idle at 900 with 8 - 10 degrees of initial timing. La ditta Zingerle fu fondata nel 1922, all'epoca ci occupavamo della commercializzazione di orologi meccanici e del rilevamento manuale e meccanico. 2) Tasso Jets and 22mm Carburettor. Recheck the timing setting to insure that the distributor did not move while being tightened. Carburetor adjustment does not require an engineering degree, but some mechanical ability is necessary. Available aftermarket carbs. While there seems to be an Carb gaskets - Confirm that these gaskets have a soft drying sealer (like Gaskacinch or Permatex Hi-Tack or 3Bond However having dual carbs is not necessarily the passport to big time horsepower. Live Timing. Tuning and Jetting: Do I Run a Single 45 or Dual 40's? Tuning and Service PDF (2 meg file size) Weber Resources on the Internet: User Photos and jettings Adjusting Twin DCOE's: The Fuel Flow Path: Physical Dimensions: Excellent Article by Mickey Luaria: Virtual Tour: Rasors Fuel Flow Pathes: The Jetting Calculator-----An email from a Racer. We can setup and tune most stand alone ECUs and many OEM computers. 5 turns may be ok. Even as we struggle with the COVID-19 pandemic, it is critical that we continue to support. RM250/370 Jetting change 17. 95), this book has some good general information that applies to Keihin as well as Mikuni products. The effectiveness of a consuming a carbohydrate and protein shake immediately before and after exercising. RM100 Primary drive/driven gears 20. Hg below (numerically less. ADVANCED TUNING: If you want to experiment with the other circuits of the carb (Mid & High), you will need to remove the carb from the engine, drain and remove the fuel bowl and unscrew the jets on the bottom side of the carb. There are two types of vacuum sources that you should be aware of. A saw with a properly adjusted carburetor will produce maximum power, minimal smoke, run and idle smoothly, and give trouble free service. Problem- my 500t will start and has a nice idle around 1500rpm. Knowledge is power and whether you are tuning your car yourself, wanting to start a career as a professional tuner or even if. The benefits of gas flowing. I set the timing to 18 after the engine was warmed up and idling at. Low Carb Kung Pao Beef. Mikuni Carburetor Tuning. It's a platform to ask questions and connect with people who contribute unique insights and quality answers. i am hearing that either a green cam on secondaries or bigger squirter and jets, or a combination of all. - A1-A7 Specs extracted from the GPz900R Workshop Manual, - A8 Specs from the Kawasaki Dealer- microfiche. The only way to tune the engine properly is with an air fuel ratio meter. carburetor venturi from below the throttle plate (where it was exposed to full manifold vacuum at idle) to above the throttle plate, where it saw no manifold vacuum at all at idle. Joined Mar 2, 2002 · 671 Posts. Follow your engine manual and make an easy. For example, here's one such guide. 5 pilot (rich) 57 needle 2nd clip 310 main Timing: 17deg BTDC to be safe Exhaust: Franspeed Tourer Engine: TS1 225. speaking of air drying, let the carb air out for a bit with out the drain plugs in, like go have a beer. Usually this means when during the day, morning versus night, but it can also mean relative to exercise or other activities. WEBER Carb Tuning Tools. Advanced timing helps cooling. Disconnect the timing light. Hi guys/gals, I have a 1984 FLHX Electra Glide Special with a shovelhead engine and Keihin butterfly carb. When experimenting, advance the leading timing in 2° steps to find the optimum setting, then advance the trailing in 2° steps to find its best position. Also you might want to check for vacuum leaks between the carb & the engine. A good starting point is 8º before top dead center (BTDC) static timing or at low idle. First, JRT is a Timing Table with Real Time updates. the car (65 nova) ran 11. Tune up the rest of the engine- REALLY! clean or replace, and set the points, set the timing, plugs, valve lash, and remove the air filters. 3, twin gt35. We offer excellent customer support, quality online registration, and accurate event timing. Otherwise you will get very high timing readings. I cringe every time someone buys 8gram weights for a bike that came with 7gram. With two adjustment screws in the front of the carburetor, you can adjust and tune the carburetor in just a few minutes and have your engine running smoothly. Adjusting and setting the timing is an easy process but just need some simple hand tools and a little bit of patience. Could be a carb problem or a bad vacuum leak. It easily connects to any. The IMC tuning method was developed for use on selfregulating processes. Advanced timing helps cooling. I have read 16 and 14 BTC but the car seems to like 12 better. With the crank in this position the meter should read 0 ohms, or no resistance. running competitors carb with C/S mechanical pump plenty of fuel psi typically 7 psi. rons toilet/terminator running methanol. 4)set to color tune. Could anyone tell me the correct timing setting for a B175?. timing is stock curve #4 pill total is at 36 i believe. Intel® Extreme Tuning Utility (Intel® XTU) makes overclocking easy. When tuning, start from the beginning, making sure that all other engine systems are in good working order (ignition, vacuum leaks, etc) then go from there. We cover the key effects of VVT and its benefits on a turbo Medway took his recalibrated tune and pasted the factory MIVEC maps back into it and reflashed the ECU, he then compared the dyno results to his. Then go and adjust your carb idle mixture screws with the gauge still plugged in. Contents[show] Terminology Lean: referring to the tuning of a carburetor in which the fuel/air mixture contains too little fuel and too much air Rich: referring to the tuning of a carburetor in which the. Quick Fuel Technology® (QFT™) ships carburetors only after they have been thoroughly run-tested and adjusted on a typical engine. Any adjustments on rear carb have zero effect on cars running behavior. Again thank you all for the great advice, and happy RVing to you all. pdf), Text File (. Re: Holley Carb Tuning Debate « Reply #18 on: May 29, 2008, 08:14:12 AM » BTW - I ran my boat yesterday - Tunnel ram, twin 450's, 8. Timing incorrect - - Check timing with light, lube/replace advance weights if used. Your timing mark will now go off the scale (more that "just beyond" the marks), and the engine rpm will pick up noticeably. Adjustable valve timing Carb jetting Carb jetting at the bottom end Main Jet LCA Valve timing Valve to piston clearance valve spring and guide clearance set valve clearance Tyre speed rating. You can easily change the tune of your own LT1! For the average computer user and car enthusiast, there isn't much to it! With an initial financial investment and some time set-aside, you can get your car running great and take advantage of your mods. Starting from AGESA version "Combo-AM4 0. Carb Tuning. Most control loops, e. Hg below (numerically less. Motor timing depends on induction a lot, and induction also depends on many factors such as the loads (current), coil resistance, coil number of turns and so on. I had to drop the gas tank and give it a major cleaning and then repair holes in it by fiber glassing over them. As soon as the weather changes, track condition changes, or other changes are made (like valvetrain lash, spark timing, etc. Correcting the NT and Speed carbs. Want to know what those screws and jet needle slots do? Tuning Mikuni piston slide carburetors, the basics. Its relevance to a given individual depends on that. For years, we've been using oxygen sensors as a tuning aid, hooked up to one of many aftermarket display gizmos that convert the sensor's voltage to. Our Power Commander tuning device is a powerful device that can completely overhaul your driving experience. I am running 2. What happens sometimes is the initial timing is too low, causing the primary butterflies to be opened so far to get the engine to idle that the engine is not running on the idle circuit; instead it is running mostly on the transition slots. should get yourself a synching tool to "synch" the carbs. Arctic Cat 900 twin engines fitted with carbs come with Mikuni rack style flatslide (TM-40mm) carburetors. Best of luck and let us know what you find. Also you might want to check for vacuum leaks between the carb & the engine. Let's set the top end first since it's the easier of the two. I have been in business since 2014 and have been doing EFI tuning since 2009. Sometimes velocity stack length can help here, but a pipe that has it's resonance timed incorrectly for the range of operation that you use the most, will cause you hours of unnecessary grief trying to get rid of the flat spot. Carburetors simply perform better with ethanol-free gas and you should probably be using ethanol-free all the time, but if you aren’t, just start cycling it in before you tune your carburetors so that your fuel supply will be 100% ethanol-free by the time you get around to tuning the carbs. Then retard the timing until the vacuum gauge reading drops slightly, approximately one half to one inch. Remove the pipe plug and attach your vacuum gauge to measure intake manifold vacuum. Sections of this page. How- ever, they had their own problems with frothing and slide breakage. Low Carb Kung Pao Beef. This requires using the #5 or #8 plug wire to trigger the time light. Cycling at racing intensity must be fuelled primarily by carbohydrate, and we know that the body is able to store only enough glycogen (carbohydrate in its stored form) for around 90. The term carb cycling encompasses various strategies in which you rotate periods of higher- and lower-carb eating.