jetting question for an 03 warrior

[gsxr-rider137]

ok..what is the stock size for the main jet..i think it was changed by the original owner. and if it was, would you have to change any of the other two jets that sit in the bowl?

i have an issue with my sled.....it runs fine but stumbles slightly on hard acceleration, before taking off. if i pull the choke 1/3 of the way out..the sled doesn't stumble and seems to pull harder. i pulled the carbs twice, thinking they were dirty, but they were't. i think i remember the guy i got it from telling me he went up a few sizes,,,and when i cleaned them i saw the main jet was 135. he also opened up the air box snorkel a little bit and added a breather to the crankcase so it doesn't dump hot air in the air box . all of this makes sense, but is it causeing the stumble??

 

[kaj]

135 is stock jet, opened up the air box= more air, ned more fuel=bigger main jet.

 

[LazyBastard]

That previous owner was a MORON.
You can't just open up the airbox on these - the carbs are very delicately balanced and won't work right if there isn't enough vacuum - these are CV carbs, there are TWO throttle valves, one is a standard butterfly valve, operated by the cable, the other is a slide, operated by VACUUM. Cutting the opening in the airbox open more will NOT improve performance - it will actually HURT it. If you can, put it back to stock. If you can't, you'll need to EXPERIMENT with aftermarket carb springs and jetting.

Also, put the crankcase breather back to the airbox. The intake vacuum helps to reduce the crankcase pressure. There really isn't any significant flow from the crankcase, it certainly isn't filling the intake with lots of hot air.

 

[gsxr-rider137]

ok...i might try that and see if the stumble gets better. i was also considering raising the needle a spot or two..to see if i can get it to clear up. any idea if that might be alright to do with the mods done to the sled already? i love the way it pulls and any would like to make it better in any way i can without draining my wallet..i have a drag bike that owns that area already........

thanks for the input!

PS: what will carb springs do for improvement?

 

[suprfst]

The lighter carb springs allow the slides to open easier,also helps throttle response.When you get more air flowing into the carbs by opening the air box or adding filters it loses vaccum that it previusly had.So you need richer jetting and weaker springs on the vaccum style carberators.How much richer you need to go depends on how much it was opened up.

 

[pat the rat]

you's guy's are all wrong,they didnt even make a 03 warrior ha,ha,

 

[gsxr-rider137]

it was originally a mountain...i removed the big track and replaced it with the shorter on.......isn't that a warrior?

 

[suprfst]

I think what pat the rat is getting at is yamaha didnt start making the warrior untill 04,I didnt even think about that untill he mentioned it.

 

[gsxr-rider137]

 

[pat the rat]

just havin fun guys

 

[gsxr-rider137]

i aloso read an thread in here about longer main jets.....to reach deeper in the bowl.any thoughts ion that?