My brother's 250R isn't quite running right. We noticed that it runs great, but then seems to break up at higher RPM's after a while (after it warms up a bit). We noticed that after it starts breaking up that fuel is running out of the overflow tube. Seems obvious that this is a float level issue.
He's running a PWK Airstryker carb (bought brand new). We haven't pulled it apart yet to look for junk or crud keeping the float needle from seating properly, but my question is regarding the alignment of the carb itself. Is it critical to have the carb leveled or oriented in a very particular angle? We are using a commercially available intake boot and the stock airbox, etc... so the angles should be comparable to those of the standard carb. Has anyone ever noticed a sensitivity to how the carb is rotated in the boot or aligned?
Hopefully it's just some junk in the float needle keeping it from closing properly. Of course, if it consistently pukes out the overflow tube, we can lower the float level. But it seems to be ok at times, and not at others so it makes me think it isn't the actual float level tang adjustment, but rather debris.
Just in case if anyone has any other advice for troubleshooting a breakup at higher throttle, I'm open to suggestions. (other thoughts are coil, cdi, reeds, and of course jetting)
Thanks!