Need help adjusting carb
 

I have a MVVS .91 with the older ( #3222) style carb. I believe this carb is also referred to as a Prettner style carb. Can someone tell me how to set it up to get the engine to run? Thanks.

RE: Need help adjusting carb
 

The 3221 and 3222 are butterfly type carbs. They have a butterfly stop screw near the lever, and on the other side of the carb the large main needle and an excenter type idle setting plate.
First set the butterfly so it will admit mixture to the engine. A modelling pin should be able to just pass.
Then the main needle should be set at about 3 turns open. A primed engine should now be able to start at wide open throttle. Adjust the main needle leaner, until the engine falls into a nice even firing with just a very occasional fourstroking miss.
Now slowly reduce throttle. If the engine goes rich, the excenter plate should be moved clockwise, and vice versa.
To do this, first loosen the set screw (nearest to engine) Now the excenter screw can be used to adjust the mixture. Clockwise is leaner, anticlockwise is richer.
When done, idle transition should be crisp. If the engine hesitates, slighe richer idle is needed. If the engine stutters, a leaner idle is needed.
Gently fasten the set screw, and you are done.

RE: Need help adjusting carb
 

Pe,

Thanks very much for your help, it is sincerely appreciated.

Paul.