rebuilding is a misnomer for all but the really bad ones.I prefer to take them apart ,clean and look for problems.Replace bad parts.Sometimes everything can be reused.Shake the float,if it rattles it leaks and will sink.Check all passage ways with gumout can w/red stick.Make sure the ball is in the accel pup circut not lost.Visually check jets.Pilot jet has very small hole .Comp air is sometimes not enough if cloged.Use a paper fuel filter when done.Don't overtighten brass or air horn screws.New parts are occasionaly wrong.I found one carb had a .004 too small unlabeled main and a .003 to big power valve needle.That created a cold blooded demon that belied fixing for years, and may 'rebuilds',Then it was handed to me....Best advice is understand the function then go at the problem(assuming it has onel)looking at the specific area.Ex: if it doesn't idle check pilot jet,float level height,inspect bowl and fuel in there for dirt and water,see if adj screw responds and both ends of range,check for vacuum leaks at base or manifold,check fuel filter/pump prssure/compression... Find something related and fix that then start it with confidence.Often a generic 'rebuild' ends up cleaning and new parts but no important change is made so it runs the same when done.Then again sometimes a carb needs a good cleanin' and some new parts. JimK
