You can have lots of things done incorrectly, and if someone didn't know better, while it wouldn't be at it's best, they'd think it was normal. A cold or partially warm engine will give you inconsistent/inaccurate jetting results. You need to go back to the middle after each turn. This usually get you to the center of the adjustment range. This will decrease the amount of fuel getting in, i.e, making it leaner. The idle screw is on the top of the carb, away from the engine. So, your'e saying that eliminating the stock air box while also running the V&H Short Shots requires re-jetting and that backing off the PMS setting simply won't have the desired effect? Doing this at the start will help you understand how the fuel screw and jetting circuits work. One simply adjusts the air and the other adjusts the fuel. Turning Out (counter-clockwise) = Richer - you are turning the taper of the screw away from the opening and allowing more fuel to pass. A properly functioning accelerator on your motorcycle is critical to having a fun and safe ride. If you fill out your bike and jetting info in your profile that would help us help you. the fuel screw the fuel mixture, and the idle screw controls the idle mixture. There can be issues with the timing chain tensioner allowing too much slack in the chain and allowing the timing to be off. There can be several different reasons why an engine would have issues starting. Also, it may sound like you always need to accelerate in order to pick up. Also, keep an eye on the air filter condition and replace as needed. Thumbnail Filmstrip of MaxMix Images. Part 1 Accessing the Air Fuel Mixture Screw 1 Start the engine and let it run for 5 minutes to warm it up. Fuel cock (page 3-7) 3. It usually sits on top of the carburetor. "Yes, I really didn't know how to adjust the carb fuel mixture. The fact is, the instant you change your RPM, up or down, your manometer reading will change. Most engines have an ideal air fuel ratio, or AFR, around 14.7:1. Step 2: Adjust the air fuel mixture. Of course, this is all dependent on preference. CV Performance has exclusively provided Harley riders with the EZ-Just for over 30 years. Syncing refers to adjusting each carburetors idle to where they are synced. Sync the carbs first. This also means that you have to keep in mind which you are tuning so that you know if youre going richer or leaner. Make adjustments with the engine warmed up and running. Before riding, give the bike a thorough inspection, looking for anything that could indicate a larger issue. Check for stuck open floats. The final drive will need the oil changed regularly. Then, go back to the middle point. Then back them out slowly to the point the idle just comes back up. Generally the pilot screw adjustment procedure involves turning the pilot screw in or out in small increments until the idle climbs as high as it will go. As with any bike, keep up on general maintenance to keep the bike in good condition. Turning the fuel screw out increases the fuel, making it richer. It is now down to a pleasing crackle which I can live with. Counterclockwise adds more fuel to the idle circuit, clockwise takes fuel out of the idle circuit. Do not post these threads in any other forum. Review this product. The original EZ-Just mixture screw for Harley CV carburetors adjusts the air idle mixture. To adjust the air/fuel mixture screw using the static method, first remove the carburetor and find the air/fuel mixture screw. The mixture screws are under the float bowls on the engine side of the carbs. Good luck B Bigs Registered Joined Mar 24, 2008 Loosening the screw strengthens the air and fuel mixture and increases the amount of fuel flowing to the engine. The Fuel Ratio screw is probably plugged. It has a great style which can be customized to fit your preference. I have one of the old original Carb Stix tools, the one with mercury in it. NOTE: Set them accordingly (they are NOT the same as stock PMS screws!) MaxMix. The PMS screws taper to a point. As has been mentioned, the 650 has enough power and gearing to cruise on the highway. No need to re-jetted just for the pipes. All times are GMT-6. No motorcycle is perfect, so just make your own best judgement. The safe bet is to go with OEM parts unless you are confident in your abilities. The logos and trademarks used on this site are the property of their respective owners. The throttle cables seem OK. For example, if you turned the screw 2 full turns counterclockwise from the spot where the engines idle started to sound rough, now turn the screw clockwise 1 full turn. (No fuel injection, though!) If you do, they will be moved or deleted as they are found. Yamaha also offers Star touring bikes, but again not in the 650. There is no magic fixed setting, just a range of adjustment. Keep some spare parts and tools on hand in case of an emergency repair. Not really, the idle adjustment is just lifting the slide (adding air and fuel together) where as the mixture screw is adjusting fuel only. 7) Now slowly turn the mixture screw in (clockwise) until the idle speed (RPM) drops about 50 RPM. (41 pages) Motorcycle Yamaha 650 Buyer's Manual. To adjust the idle, simply turn the idle screw in or out until the engine stays running at a smooth RPM. I was expecting to get some push-back from the manometer and the dead-cylinder crowds on this. It may not display this or other websites correctly. This image is not<\/b> licensed under the Creative Commons license applied to text content and some other images posted to the wikiHow website. Well, finding the middle between a rough and a revving engine should fix your problems. Screw the PMS screws in until they are lightly seated A) if you think you can tune it by ear then run the screws out about 3 turns with stock screws, run the bike and see if you have popping on deceleration, if you do then turn them out in 1/8 increments until the popping goes away and you will be close enough. And saving gas now, thanks very much, it saved me some dollars. Tighten the screw. Buying a used bike comes with its risks, but with some careful navigation, you can find a great motorcycle at a fair price. I've always just turned the air or fuel screws till the bike ran . If the carbs have been worked on previously, they will probably already have had the covers removed. If adjusting the PMS alone is sufficient, what direction do I rotate the PMS screw to add more fuel to the circuit? With the engine at normal operating temperature, adjust all the idle mixture screws until the engine idles at the desired rpm with the highest manifold vacuum. If you ever want to start fresh, turn the screw clockwise until it is lightly seated, then back it out about 2 turns. By using our site, you agree to our. Be the first to answer Jul 08, 2013 The spring loaded one is the idling screw. ). I agree with most things you are saying. Somewhere where you wont disturb any neighbors. Drill a small hole in the cap and either wiggle the plug. This is accomplished a few different ways. That should be your ideal mixture setting. This may require the use of hand tools, however, many times the air filter and housing are secured using only a wing nut that can often be removed without using any tools. 03 650 v star classic: what is the factory. Make adjustments with the engine warmed up and running. Less than 1 turn points to the opposite. Posted on Last updated: November 21, 2022. That seems to help alleviate popping out the exhausts on decel better. A 4 stroke dirt bike carb has a fuel screw and a 2 stroke dirt bike carb has an air screw. I have a set of V&H Short Shots installed (no baffles) and have not done the AIS delete as of yet. (function (d, t) { To adjust the PMS screws you need to drill out the brass caps that seal them, this requires removing the carbs. If you are a seasoned veteran of motorcycle riding, the 650 will still hold its own, but you might feel a bit underwhelmed. wikiHow, Inc. is the copyright holder of this image under U.S. and international copyright laws. Clutch adjustment 2004 v-star 650. To adjust the PMS screws you need to drill out the brass caps that seal them, this requires removing the carbs. Will adjusting the PMS setting to enrichen fuel mixture alleviate the problem or must I re-jet the carb? Check spark plug wires and coils and replace as needed. wikiHow is where trusted research and expert knowledge come together. Keep in mind that 1 turn on Tim's Screws = 2 turns on the stock screws. While there are a few common issues to be aware of, and after taking careful consideration of the specific bike youre interested in, the Yamaha V Star 650 will provide a great ride for commuting or adventuring. There are huge advantages to properly jetting a carburetor, and theres also huge disadvantages to NOT tuning your carburetor. Essentially, their Can A Loose Motorcycle Chain Cause Vibration? It's an idle mixture screw. V Star 650 motorcycles are pretty popular and were produced for a number of model years. With so many model years there are plenty of used bikes to search through, although availability is dependent on the local market. More Info: http://mylittlehomestead.com/moo-how-to-adjust-motorcycle-idle-screw-yamaha-virago.html https://twitter.com/mroffandonDIY: How to adjust Idle Scr. This can make performance a bit unreliable as additional tuning is required to compensate for the different jets. So drill a little hole not to deep you do not want to be hitting the screw behind the plug. You are looking for that normal idling that your car used to have. If you have never ridden a motorcycle before, this may not be the best one to start out on unless you are in a very controlled environment. And another: mitchyd - drilled and taped the PMS screw ran a nut up the small screw/ bolt against the head with a star washer for grip JB weld into place so doesn't vibrate apart: And another: Tundrawolf: I used a 1" Copper Rivet (Hardware store 25c a piece), Oatey Water Soluble tinning flux (for joining dissimilar metals) (Lowes Under $3 I think), a cutoff disc on my Dremel to shape the end of the Rivet -- The final result was a small slit that fit snugly into the notch of the mix screw. Here is what I did for my 2000 with AIS delete, Sideburners 2 into 1 aND round K&N universal filterruns great and 43.5 mpg mixed driving, for the 1700 with K&N filter and no baffles. 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