oil pump '85 70HP Yamaha

[007wa]

I have a great older little center console boat with a '85 70HP 3 cylinder Yamaha outboard with oil injection. I have had no problems with this engine for many years until recently. The past couple times I' ve started the motor it smoked for a couple minutes and then went away. I ran it for several hours and it worked fine. The last time I went to start it wouldn't turn over. It acted like a weak battery or bad starter. After checking both out and determining that both were ok I pulled the spark plugs to see if the engine was seized. When I cranked the engine it cranked fine but, it blew out about a quarter pint of oil out of the bottom cylinder spark plug hole. I put the plugs back in and the motor started up fine, smoked a couple of minutes and then ran fine for several hours.

Do I have a bad oil pump that is leaking oil into the cylinder while sitting unused? Any advice would be greatly appreciated.

[boats.net]

It sounds like a bad pump, probably a seal leaking in back of pump or the internal check valves are bad. The new pump you will get will have inline check valves which will resolve the problem.