thanks ,i do open it up thru out the 1/2 hour many times im sorry i didnt explain that,but after the 1/2 hour or so when i open it up it fouls out. i run it the same way i use to and the plug use to have a nice brown color to it but now after the rebuild it is always black and wet and smokes alot more than before. the guy that rebuilt it said the 1 crank seal was pushed out and could have been leaning it out. could it have been that way a long time and the jetting was always rich and the pushed out seal compensated for the rich mixture ? or does boring the cylinder out 20 thousands  change the fuel/air mixture ?

The crank seal on the transmission side may also be pushed out allowing the engine to be consuming transmission oil.  It is time to do a pressure test on the engine.

Boring the engine .020" will not change the jetting.  A plugged up spark arrestor will make the jetting act rich.  A dirty air filter can make the jetting act rich.  A broken reed petal will make the jetting act rich. 

Pushed out crank seals are usually the result of a carburetor flooding the crankcase.  If the crankcase is full of fuel when it is pushed or kick started, it will often break a reed or push the seals out of the case.