B&S model 23

[deereowner]

I am working on a cast iron model 23 engine. I cannot get it to idle. Actually it runs away with itself. I installed a new Chinese carb i bought from eBay. Had to reconfigure the throttle so it worked on this engine. The carb may be from a model 19. I have installed a new governor spring,condenser, and spark plug. I seems to be getting too much gas as it blows grey smoke, adjusting does not help. Throttle throat on new carb is larger than old carb. Where do I go from here? Mike, Florida.