250R jetting

[Iliketogofast]

I'm having a problem fouling plugs at low speed, also I get really ****ty throttle response until 1/2 throttle, and the quad doesn't rev all the way out in 1st or 2nd. Somebody told me (Beerock, I believe) this was jetting, it would be pilot jetting, correct? Or am I jetted bad in both or just main? Thanks

[Iliketogofast]

Please???? I need to go get the new jets! Thanks

[xx3003xrdrxx]

2 strokes arent met for low speeds . Riding them soft is what will foul the plugs in a heartbeat . The ****ty throttle response is because your not in the powerband ....

[Iliketogofast]

No, the ****ty throttle response is not because I'm not in the power band. I know what I'm talking about, and I definately know what the bike feels like when properly jetted. I just need some intelligent feedback on the issue before I act on it, and that's not what I got. Thanks anyway...

[wilkin250r]

Calm down. You're on the internet, you've got to expect bad responses every once in a while.

Forget "speed", forget "gears". The carburetor doesn't know what gear you're in, so it doesn't make any sense for you to say it doesn't rev all the way out in 1st or 2nd".

Really, the only factors are throttle position, and engine RPM. And of those two, throttle position is MUCH more important than engine RPM. Your jetting is determined by where your throttle is located, not what gear your in, and only slightly related to engine RPM.


So, with this new information in mind, describe your problem to me. Don't tell me gears, because they have no effect. Describe your problem in terms of throttle position.

[Iliketogofast]

Ah... thank god. This is the intelligent feedback I was talking about ;) Okay. I get the bike warmed up, taking passes up and down the road. After it's warm, I can get to a good pull in the meat of the powerband, but it lags in the lower end. Once I am in the meat, I don't get any throttle response whatsoever until I get to about 1/2 throttle. It also fouls at low speed, and while I understand that this is somewhat normal for a 2 stroke, it should not happen this often. It happens every 2 rides or so. I might add that when I take the airbox off, the bike runs great. So I'm pretty sure I'm jetted wrong, but I thought main jets controlled over 1/2 throttle, and that's not where it runs bad. By the way, I think the 1st and 2nd gear thing is solved... I need a higher rev ignition, it winds out too fast and hits the limiter. At least thats what I'm guessing; the tires spin really bad on the pavement, and that's where I've been running it since there is snow.

[wilkin250r]

It's not uncommon to foul plugs at low speed, but it doesn't HAVE to be that way. Mine never does. It sounds like your pilot jet is a little too big. What size do you have in there now, and what size is your carburetor?

However, your pilot jet really only controls very small throttle openings. Even at 1/8 throttle, you're off the pilot and you're on the needle. If you still have problems at 1/2 throttle, you might want to raise your clip a notch (which lowers your needle, and leans your mixture).

What kind of diagnostics have you done? Have you done a compression test? A Leakdown test? Plug chops? Check your reeds? New Spark plug?

[bwamos]

I would agree with the needle observation.