Good day, eh, from Canada. I am having some serious issues with the P216 Onan in my garden tractor and I was wondering if any of you could provide a little insight into my problem. It all started earlier this year when I mentioned to the local Onan shop that my engine seemed to lacking power. I was told to pull the heads and de-carbon the valvetrain, etc. I did as was suggested and also lapped and reset the valves to factory spec. Since then, the engine will blow so much oil/vapor out the vent tube that it accumulates in the air cleaner then spills out all over the engine. I pulled the valve covers several more times to ensure the vent was working and the valves were set properly but the problem seems to be getting progressively worse. This weekend as I was cutting grass, I pulled the dipstck and hot oil shot out like it had 20lbs pressure behind it. Yes, the vent is working properly....yes, the valves are set correctly....yes, there seems to be adequate compression(85lbs approx). The engines starts perfectly and runs/accellerates perfectly, but I cannot come up with a reason for the excessive crankcase pressure. I've never had one of these Onans apart before so I don't know if there is a pressure regulator screw on the oil pump or what all else is in there. Any bit of advice as to what to check or where would be greatly apprecited.Thanks.