when i bought my 450, it was too lean so i changed the pilot and went to a 45 from a 42. it still pops so this is indicating that it is too lean. i have played with the air/fuel screw and it seems like i have it right on now but i dont know too much about jetting and i am curious to find out if my bike is running as well as it possibly could. put it in mind that i ride in the desert of socal.

i just rode my bike...when i opened it up above half throttle, and rode it hard certain times it would pop in high rpms. anyone experience this? i was thinking i was going to up to the next size main jet. any help is appreciated

Have you checked for leaks,, you will never get the jetting right if there is a air leak somewhere

leaks in the carb? i checked all the bolts and they are as tight as i could get them

My 426 would have popping just like how your explaining. I didn't think much of it, considering it was only in the upper rpms but in time it got worse.. Come to find out. A piece on the headpipe was broke and loose and it was leaking around there. If there is a leak on your exhaust anywhere, it could be sucking in cold air which is making your bike pop in the upper rpm's.. Just a thought. Might not be it tho..

thanks ill check that. i would be pissed if that was the case seein on how i bought the bike 2 weeks ago

Same-o on checking all connections. Even a small leak will lean the mixture a whole lot. Also, it also takes a pretty long time to warm up the engine, since the oil is carried and cooled in the frame downtube. Mine takes about 2-3 minutes of slow riding before fully warm and then runs clean. Good luck.

I run my bike at 1/3, 1/2, 2/3 for long periods at those steady speeds (like dirt road). It was running rough at 1/3, I went from a 45 pilot to 48 (Cdn bike has 45 stock)...problem solved. It ran a little rough at 2/3, so I went to a 172 main, problem solved.

Obviously, different conditions I am riding 900 feet above sea level and in 70-85 degrees. Considering how quick it is to change jets do it until you get it right. I have found the 450 to run a little lean on the pilot circuit.

Good luck,

Vet28 :thumbsup:

i changed my pilot from 42 to 45. that helped alot. now i think im gonna go up to a 168 or 170 main. hopefully that should make it run well.

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