Stihl 021 Won't Come Up to Higher RPMs

[hotajax]

Saw starts OK, and seems to idle OK. But when I nail the throttle, rpms rise maybe halfway, then the saw cuts out. Seems very smoky. If I cut back on the low side, the saw won't run. Is this a high side issue? Fuel is daisy fresh, carb two or three years old, but hasn't seen that much use. Thanks in advance. It's an aftermarket Chinese carb.

 

[brushwacker]

Remove the air filter and see if it makes a notable difference how it runs.

 

[hotajax]

No diff, but.....it's fixed. I had the high side way too rich and it kept stalling. Leaned it out and now she screams. But I gotta get a tach so I don't over rev.