in your first post you said it was running ok and then started ideling high, this sounds like an air leak. since you've had the carb off many times i'll assume it's seald good there. take off the clutch side cover and see if it looks like gas is leaking in to that side. could be a crank seal leaking. the mag side could leak too, but since you've been in that side already and haven't said it was all wet in there it must be ok. if it has compresion, fuel and spark, it has to be a mixture problem, and an air leak would cause these symptoms, it can leak air at the crank seals, the manifold to jug gasket, the carb to manifold clamp area, or the seam where the 2 halfs of the engine mate.
this is a little in depth for a beginner but you can block off the exhaust and seal the intake with a cap that has a tire valve in it and pump a few psi of air into the engine and check for leaks with soapy water, any bubbles are leaks, don't use to much pressure only 3 or 4 psi is needed.
this is a little in depth for a beginner but you can block off the exhaust and seal the intake with a cap that has a tire valve in it and pump a few psi of air into the engine and check for leaks with soapy water, any bubbles are leaks, don't use to much pressure only 3 or 4 psi is needed.