Re: Johnson 15hp motor with carb trouble???
As others have alluded to here, a pretty carb or a clean looking carb, is not necessarily a functioning air/fuel mixture making machine. When people say your carb is dirty what they really mean is that the holes in the carb passages (jets) are not the diameter they used to be because of some foreign matter. Usually but not always it isn't dirt clogging it up, it is dried gas residue everybody calls gum or varnish because it acts just like varnish. It requires dismantling the carb, removing the parts, soaking the non-metallic parts in carb cleaner (not just spraying the outside till it looks good), blowing them out with compressed air, and then installing the new parts that come in a rebuild kit. Most of these carbs are pretty simple, they're not Webers off of a Ferrari and if you have a manual you can do it yourself. As often as these things clogg up you should probably learn to do it yourself unless you have wads of cash in which case you wouldn't be on this forum anyway. Bite the bullet, buy a manual and a big bucket of carb cleaner and just do it.