PWK Airstryker Setup Question - 85 250R

[wonderboy]

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!

[yaegerb]

No particular orientation required other than bolting it on. Airstrikers were designed for keeping fuel moving on mx courses so I would check to ensure float level is within spec. That motor should run just fine with a 170 main, 50 pilot and needle clip 3rd from top. Also ensure that your stator wiring is in good working order, woodruff key not bent, your pulser wiring is good, pulser reader doesn’t have rust on it and that your pulser air gap is set about the width of a business card.

[wonderboy]

Thanks yaegerb. I hadn't thought about the stator and related stuff. That's a good call.

[RubberSalt]

Was this a legit air striker or a china one? I did a tear down of the china and found orifaces being way to small. No jetting could correct it. Orifaces smaller than jets.

[wonderboy]

That's a good question. It's my brother's machine, and I think he bought the carb from one of the legit on-line dealers (not ebay) but I'm honestly not 100% sure. I do know that it has run very well at times. Once I get time to head back home and help him look at it (he's 2 hours away) we're gonna check all the electrical items out but then focus on the float level and make sure it is solid (seems to be good then bad for no reason). But when it was running clean, it was running very well, so I don't think it is a carb manufacturing issue (china crap).