Fuel screw--no affect

I got a chance to ride today, so I got the bike warmed up after a 30 minute ride, then I decided to adjust the fuel screw. My recollection was that I was to screw it in until I noticed a change in the idling engine, then back it out a 1/2 turn.

Well, I turned it all the way in from 2 turns out with the bike idling, and no effect except possible the idle increasing a bit. My purpose in doing the adjustment was just o make sure that I didn't have it adjusted wrong. I can't complain much about bog, etc. since doing the JD kit, free mods, etc.

Was I doing the adjustment right?

If you turned it all the way in (leaned the pilot circuit) without any effect, you probably need to go one step lower on the pilot jet. Try a 45 if you're currently running a 48 and see what happens.

BTW, to tune the screw, raise the idle to 1900 rpm, turn the screw all the way in and then back it out in 1/4 turn increments, allowing about 15 seconds at each step, until you get the best idle.

Are there any other symptoms? Or is it running OK?

It is running pretty well. I have to really hit the throttle from idle to experience a bog. And, it probably could use a bigger starter jet. So, I can't complain much!

FYI--I got a big performance increase with the PMB insert into the stock muffler. The other free mods didn't have much of an effect that I could notice.

So, for the fuel screw, I want to get the idle to 1900 rpm; then, turn the screw out 1/4 turns until I "get the best idle"? Can you explain what best idle is? Do you mean an increase in idle or smoother idle? Thanks!

getting any backfiring when reving the engine?

I'd be checking for air leaks. A small air leak can cause all sorts of problems for your jetting.

Can you explain what best idle is? Do you mean an increase in idle or smoother idle? Thanks!


Read through this page. There are a ton more like them in the FAQ at the top of the 250 forum too.


And nope, no backfiring or popping at all on deceleration or otherwise

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