I have rebuilt the carb. Everything is new; jets, floats, gaskets, seals, o-rings. Carb is completely clean and all air ports are open. The engine will idle very smoothly & will accelerate to the max. The manual calls for the air screw opening at 1-1/2 turns open. You cannot keep the engine running at this setting. The engine idles smoothly at 1/2 turn open. My problem is: from idle to slow acceleration it is erratic, rpms up and down until full throttle is obtained. Any ideas what might be wrong? Thanks. Chuck

 

clean air filter?... new plug? ....fresh gas?......carb put together right?.....choke off\not stuck?..gas lines or vent tube unobstructed?...that's some of the things i would check first....good luck

 

The first thing I would do is....start it up. Then take a can of ether or WD40 and spray around the carburator to check for air leaks. If theres an air leak, you'll know by that procedure.

I would check the air filter to make sure it's clean.

Other than that, I think it sounds like a bad wire. Maybe theres one thats cracked and is causing a short. Maybe check the plug wire. It might be a good idea to start it up in a dark garage to see if there's any sparks coming from somewhere they shouldn't be.

How's the flow from the fuel tank. Maybe disconnect the fuel line from the carb and see if it flows freely/consistantly for about a pint or so of fuel.

Is the fuel tank clean?

You also might check all the electrical connections for a bad ground

Hope my ideas help

Good Luck