No matter how long i ride it when i put it in neutral it soon cuts off an i have a keihen carb anyone no how to tune it?

might be too rich at idle? giving it throttle opens the slide to give it more air to match to rich setting
Slide height set to low?

I want to tell him to throw it away for a Mikuni TM series but I know there are a couple of guys that use the Keihin with good results. 

ok so the carb i got isnt good? an i think its 39

Mikuni's just have more precise tuning abilities.

If its a PWK 58 pilot and a 180 main should be a good starting point.The main is a bit fat on mine but it has a PT pipe on right now.Better to start on the safe side.Not sure your altitude but I,m in Ontario Canada.What pipe are you running as it will affect the jetting?

I have a pwk on my Zilla its bored to 40.3 and I have a 60/180 in mine but I have hrd porting and a few other mods. Mine seems great but it took some time to get her tuned. Sounds fat on idle to me

Quote from: Rider414 on September 04, 2013, 11:49:08 am

I want to tell him to throw it away for a Mikuni TM series but I know there are a couple of guys that use the Keihin with good results. 

funny, when i was on 3wheelerworld.com, most of those guys said throw away the tm and run a pwk.

Use what ever brand or model carb that can be tuned to perfection.  The number of tune able circuits and the number of jets, slides, needles that are available from the carburetor manufacture is what influences my choice of carburetors.

If a carb manufacture made a carb that only had one circuit and they only made 2 jets to fit that circuit, it would not take long to find the jet that worked the best for that carb.  The jet that worked the best for that carb does not mean that it was the jet that allows the engine run up to its full potential.

The Mikuni carbs used on dirt bikes typically have three more tuning circuits than the Keihin carbs made for two stroke dirt bikes.  More circuits and more tuning parts in the hands of an experienced tuner usually produces a higher level of carb tuning. 

The air flow rates on the different brands of carburetors are very close to being the same as long as the same size carbs are being compared.  Every carb manufacturer has to have some type of sales gimmick to sell carbs.  Their unique design produces laminar flow, improved throttle response due to bla bla bla.................etc.  Throttle response is more about the ability to tune the carb than it is about the unique design. 

ok thanks guys i think im gonna get another carb when i get a chance