250R idle issues

[TrikeBandit85]

I just picked up a ‘85 250R all stock and i had got it running it was idling no issues then all of a sudden it didnt want to idle i tried retuning the carb and making sure my jets werent clogged or any other common issues but nothing. It only idles with choke on, any tips or tricks to fix this?

[Red Rider]

If everything is all stock, and perhaps original, on that 41 year old bike, the first thing I would suspect is an air leak, especially around the carburetor-to-reed valve boot.

[TrikeBandit85]

How would i check that? just run it and spray with soapy water?

[Red Rider]

If nothing obvious is found via a visual inspection, you can try spraying WD-40 around the area while the bike is running. The idle will increase, if there is an air leak in that area, when it sucks in the WD-40.

[TrikeBandit85]

Yeah ill try that with the WD-40 but nothing obvious with a visual inspection

[Red Rider]

Yeah ill try that with the WD-40 but nothing obvious with a visual inspection

If you're sure the carburetor is clean, I would suspect an air leak somewhere. If the WD-40 doesn't yield any results, a leak-down test may be in order.

[BOB MARLIN]

If you cant find a leak, check the jet in the middle of the carb, the one with all the little sideways holes in it. If one of those holes is the least bit clogged with the smallest speck of anything it will cause it to not run without the choke as well as other issues.
I've also had the threads to the adjustment screw holes and jet holes just wear out and leak around the threads.