I bought a new 250 in January 2015 which has never run right. It has always seemed to be running to rich , I have tried many different things but always seem to end up back to standard settings.

 

The problem is right off the bottom when I would think its running on the pilot jet. This I believe to be a common fault as several other people seem to suffering the same issues. One day it will seem ok and then go back to not running well again.

 

Anybody else suffering these issues and have found a solution ??

 

Thanks in advance.

ask a mechanic?

 Let me guess, Keihin?

ask a mechanic? ....Not really the reply I was looking for, As I said it is not just my bike it appears to be on quite a lot of them , So I am looking for advice off

someone who successfully sorted theirs.

Yes it has Keihin on it.

Thanks for the replies

Mine was sputtering a bit down low, dropped one size on the pilot, cleaned it right up.

I had this problem too , I must of had my carb off and cleaned thorough over 50 times in a couple of weeks!

I replaced the floats / float valve and and the float pin.

Make sure the float height is absolutely spot on and you don't have a bent breather tube that's interfering with the movement of the floats.

I guarantee that you have either a blockage in the valve needle Seat or your floats aren't set correctly.

I polished the valve needle chamber using autosol and a cotton bud attached to a drill using low speed.

Is it doing it in both map settings ?

Yes it is in both map settings.....

The Keihins are notoriously finicky about the pilot circuit and require cleaning by complete disassembly and blowing out with compressed air. That includes pulling the jet tower off. The other thing that can contribute to a wonky low end is damaged reed petals. Air leaks in the inlet tract or case leaks can also cause what you describe.

Start with the carb and visual the reeds while the carb is off. Check for air leaks with a can of hot start. Just short bursts while the engine is idling. Around the intake manifold and case halves. If you have a leak the hot start will change the engine not if there's a leak. Again SHORT BURSTS. The stuff is dangerous in any significant quantity.

Let us know how you get on. Knowledge shared is knowledge multiplied.