Choppy throttle when cruising

Jul 13, 2011
410
13
55
I took the bike up north for one day of riding. I put on a 100 miles on it. It ran great and my plug looked great. However when I try to cruse in any gear the throttle was choppy like its missing. As long as I accelerated and let off it was fine but when I tried to keep the throttle in one spot it would act choppy. Is my needle to lean? I thought it might be my float so I adjusted it a little but it didn't help. I was going to try a richer needle but I never got the chance. My friends blaster cruised just fine.
Any thoughts?
 
From all of my carb experience and research lately, the needle valve and valve needle will be the guilty party for cruising along at 1/4-3/4 throttle. You could've been a bit on the lean side.
 
Set you float to the correct spec. You may have to play with your needle to see if that helps. I would do a leak down test to make sure you don't have a
Small air leak.
 
My 250 was doing the same thing. Turned out my has gasket had a tiny leak. Replaced it and now it runs great and smooth. going to do a plug chop today to see exactly where I'm at. check for an air leak, that could be you're problem.
 
I did a leak down test when I put the motor together the last time. It only had 2 hours of run time on it before I took it on this last trip. I'm at the lowest clip setting on the current needle. I have two more richer needles waiting to go in. The only problem is that I have no where to ride and have to wait the next time I take it 3 hours from where I live to go test it.
 
You don't have a yard to ride around? I only have a 1/4 acre, and that's enough for me. When you put the engine back together, did you do a proper break-in heat cycles or did you just go ride? It might have developed a leak once it warmed up. Leakdown test again, it's 20 minutes of your life for insurance.
 
I live in Milwaukee so no I don't have anywhere to ride it. I did the proper break in procedure. I will do a leak down just to make sure its good. I'm almost positive that the needle is to lean. I've already went through several clip positions to richer from where I was at and on the second needle.
 
I live in Milwaukee so no I don't have anywhere to ride it. I did the proper break in procedure. I will do a leak down just to make sure its good. I'm almost positive that the needle is to lean. I've already went through several clip positions to richer from where I was at and on the second needle.

I feel for ya, I live in NY...same problem here. On the plus side, there is a nice ATV Park 20-30 minutes from my house...but I gotta haul my toys there to play. :( There's only so much fun I can have on a 1/4 acre...
 
I went the next needle richer on the lowest clip position and it ran better. Still a little chop though, not as bad. I can still go richer. I have the next size. Just gotta go up north. Going soon.