rm125 and race fuel

[NacsRacr40]

I just picked up a 2000 rm125, and it runs awesome except for when im idling. it feels like its guming up and needs to be cleaned out, but once im riding its fine. i heard from a friend that the rm's like race fuel. would that solve my problems? and what octane should i use? ive also tried changing main jets and that didnt help. the other day i also tried 75:25 mixture of 93 octane to 116 octane and it seemed somewhat better. i just dont like the fat of running such a high octane with so much lead in it. any help is appreciated. thanx

 

[SuzookKING]

The main jet has no effect on idling. You might try adjusting the air screw or pilot/slow jet.

Straight race fuel is easier to jet consistantly than pump gas or a mix of the two.

They make unleaded race fuels if you are worried about lead. If you have access to Phillips Racing Fuels (and don't mind rejetting for an oxygenated fuel) you might try some B35 (oxygenated & unleaded / should cover your octane needs as well R+M/2 101), I have used it in a couple of bikes now 80cc & 125cc with nice results.

 

[NacsRacr40]

it idles fine, its when i twist the throttle, its sounds gummed up. nobody around here sells that phillips gas, ill end up going with cam2.

 

[Rich Rohrich]

Race fuel is not going to magically transform a poor running bike into a world beater. Save your money and get your jetting and general maintenance issues sorted out.

 

[agitt73]

92-93octane works as good as race fuel with correct jetting
and cost alot less

 

[Rich Rohrich]

Originally posted by agitt73
92-93octane works as good as race fuel with correct jetting

No it doesn't but that really isn't the point. His problem isn't a fuel choice issue.

 

[SuzookKING]

the pilot/slow jet controls the fuel flow at small throttle openings, as does the air/mixture screw... adjust the screw if you can't get it from there replace the pilot/slow jet.

 

[bruce j]

NacsRcr40,
You should check the thread on modifying your slide from a couple months back. Sorry I don't remember exactly where it is, but you should be able to find it with a search. Basically they concern cleaning up your off-idle throttle response by using a leaner slide.