So I've been trying to start my bike after storing it for a couple months. It doesn't start unless I push start it or hold open throttle while kick starting. Cant seem to figure out what it is. Cleaned jets, new plug, new fuel, new air filter. Any tips are appreciated. Not sure if this is relevant information but bike also doesn't idle once i turn it on, must always rev a little bit and significant black gunk comes out of exhaust. Bike is a 03 CR125 (2 stroke).

Where's the air screw set at? Less or more than 1 turn out?

More, I set it to factory setting so 2-1/8 turned out.

Sounds like u may have a bad crank seal

I would take the silencer off and re-pack it just cuz you got black gunk coming out, also check the pipe just because, maybe clean it a bit. And if you had crappy gas in it your jets may be clogged up a bit. But if it starts wide, then keeps running at low rpm, I would say mess with the air/fuel mixture, jetting correct, etc. Its an older CR125. Can only be a handful of things.

Do a compression test.

Paw Paw