Fuel screw--no affect

5 replies to this topic
  • dbailey223

Posted November 25, 2005 - 04:48 PM


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?

  • bg10459

Posted November 25, 2005 - 05:51 PM


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?

  • dbailey223

Posted November 25, 2005 - 06:22 PM


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!

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  • Matty05

Posted November 25, 2005 - 06:52 PM


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.

  • bg10459

Posted November 25, 2005 - 09:12 PM


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.

  • dbailey223

Posted November 25, 2005 - 11:07 PM



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


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