I have a 80 d-50 that I recently aquired. I am guessing I am getting oil in one of my cyclnders. I get a black puff of smoke exhaust sparactically. I suspect valve stem seals, but if more how do I then fix it? Although it doesn't seem like I am consuming oil everytime it haapewn ti effects the idle and power delievery.

 

how many miles are on the motor, it could be the rings..... valve stem seals being bad usually display themselves upon startup when it will burn all of the oil that has leaked down while sittting

 

I have no idea exactly... 76k is what it says on the odometer... but I don't know if it's rolled over and how many times. It was giving me black smoke and as I understand if you are burning a lot of oil its actually blue. The black smoke has subsided, so I imagine my air/fuel ratio is just really off. I have noticed though the oil pressure runs really high according the the guage. ESP after running for a few minutes.

 

oil should be blue. black sounds like running rich or carbon burning off.