i just bought a craftsman tractor with an 11hp briggs and stratton engine, i put the engine in my roper tractor.... wht i found out was that it doesn't seem to have all that much power(8hp that used oil seemed to have more). if i go down a hill the engine revs up, on the level its alright, up hill it bogs down,wht i want to know is if this could be the fuel/air mixture screw being set to lean or do i need a carb kit. the engine revs up slow and idles down sometimes slow, the gevernor seems to be working properly. any ideas?,, thankss

Sounds like the carburetor could use some work, look for wear or play around the throttle shaft and for possible air leaks in the intake.

now that you mentioned it,, i noticed that the throttle shaft was quite loose. so would i need an new shaft and bushings? would the loose shaft account for the little bit of blue smoke when i go from idle to fast? cause it runs really good sitting in one spot and never smokes and doesn't burn oil. thanks

i got it fixed.... that nut on the govenor arm was loose and it sorta moved alittle. it wasn't over reving a whole lot but i put it down some and it runs fine now, but i did still have to put my other carb on it becasue of the worn throttle shaft, ,thanks