Small Engine Troubleshooting Problems? Ask a Mechanic Now.
good morning Ken my name is ***** ***** ill see what I can do to help
first off the torque of the engine will take awhile to find because they don't rate the smaller engines that way
secondly there are a couple reasons oil may enter your air cleaner. one of which is if the oil is to thin (has it been changed recently with the correct weight. does it smell like it has been diluted by gas?)
if the crank case pressure seems to be high then you may want to check and make sure your breather pipe isn't full of debris (grass...mud wasps)
crank case pressure is normal and it needs to vent. if you have a worn engine that will also build excessive pressure because the compression will leak from the top of the piston into the base
check those things out and lets see if we can come up with a conclusion
yes a rebuild would help for sure. if the breather checks out to be clean I would say your engine is just getting tired and sending compression pressure into the crankcase. there are leak down tests that can be done to prove that to be the issue. it involves some special tools and isn't always all that accurate though. you could try running a heavier oil or a synthetic oil to see if the issue slows down. that would tell you for sure
sounds great and please le me know how you make out Ken
any luck on this Ken?