Bad oil leak/crankcase pressure on 91 Prostar? Advice needed
So I finally got on the water for the first time since I bought my boat a month ago. Had some electrical and overheating issues that I think have been worked through. After riding for about 20 minutes I stopped to check for any fluid leaks as I replaced several water hoses and all the fuel lines. No issues but now the bilge is filled with oil. I would say probably about a quart.
It appears if the oil is limited to the right side (fuel pump side) of the engine and it looks as if it is mainly coming from high--valve cover area, front and back. I tightened the valve cover gaskets and went back to the landing; nuts were somewhat tight, but needed tightening down. I would not have thought the valve covers would have leaked that much oil in that amount of time.
The oil fill valve cover has a flat plastic push in cover that I replaced as it had no cap when I purchased the boat. Hopefully this is causing my issue. Running the engine in the yard has never shown any evidence of an oil leak. What type of oil fill cap/breather should the valve cover have? Not sure what would be the correct oil fill cap.
I plan on trying to replace the valve cover gaskets and clean the bilge somehow this morning. Any other suggestions as to where the oil could be coming from, block plugs to check, etc.?