300ex

[99_300ex]

ok so to start off when i bought my 99 300ex at the begginning of last year the choke dident want to work on cold starts really at all so this week i was thinking about it and i decied to go and jet it it had a 130 by the way so i went to a 135 and the choke mite work a little better but not much and i dont like to sit there for 10 min until its warm i dont know what to do im not sure if me jetting it like i did would have helped the problem but it was popping alot but not it is popping less so does anyone know why the choke just sucks or what kind of solution i could try and my mods are in my sig thanks and sry for the long post.

[emaxxjeremy]

a 135 sounds high to me for a 300ex. i have an 05 300ex with a k&n and full exhaust and i am only running a 128 @ sea level. i could probably go to a 130 or so, but 135 sounds rich

[300exOH]

It is possible that you need a 135 main. I am running a 135 main with my sparks exhaust, UNI filter and open airbox. The main jet doesn't affect your choke at all though. It only meters fuel at 3/4-full throttle. I changed my pilot jet to a 42 and it helped with cold starts. Just remember that the 300's are very cold blooded. Even with a larger pilot I have to let it warm up for at least 3-5 minutes before riding. You may even get away with adjusting the fuel screw out a 1/2 turn or so to cure the problem.

[300ex13]

they are right the 300 is very cold natured not as bad as the 400 but still bad...i just get it started and go get my helmet, gloves, boots and get it all on and then its usually pretty warmed up...

[bwamos]

My old setup was FMF Performax Pipe, K&N Filter (which breathes a little better than uni), and no airbox lid. I was running a 128 main jet @ 915 ft elevation. If it's popping while you have the throttle on, you're too rich. If it pops while letting off of the throttle you need to turn the air screw out a half turn.


Originally posted by 99_300ex
i dont like to sit there for 10 min until its warm

You really need to wait 5min for it to warm up. It's not good on the engine to put it under load before it warms up and all the parts expand to their proper tollerances.

Start the quad. Put on your boots, helmet, & gloves. Go grab a drink to hydrate yourself before heading off into the woods. And, by then your ready to go.

300ex's all run like crap when cold. I even touh the throttle on my 330ex before it starts to warm up it kills the engine dead.

[99_300ex]

ok well i think i understand but it wont sit and run on its own i have to be there with the throttle on a lil so do you think i need to bring my fuel screw out a lil and i dont know where that is haha im not so good with the 300 stuff yet can u take a pic and show me plz that would really help. and is the fuel screw on the outside of the carb.

[Sjorge450R]

if it cant idle on its own, adjust the idle screw on the carb...thats what I had to do.

[99_300ex]

thats even what u do in the cold sjorge300ex i kinda thought about that i will prolly try that next time i ride