A
AzCats
Member
My Powder EXT was smoking a lot and I suspected a malfunctioning oil pump discharge valve. Over the summer the entire oil tank would drain down somewhere, not a leak. I did find a bad discharge valve to one of the carburetors as a likely cause. There are 5 oil pump pressure relief valves on this model. Three go to each of the carburetors. One attaches to the bottom of the crankcase to oil the water pump drive, and the other is on a return line attached to the pump itself. The Arctic service manual states they all should "pop" at 4.5 to 5 PSI. I think they mean inches of vacuum. I used a vacuum tester and they all do "pop" at around 4.5 inches of vacuum except the one that is attached to the oil pump return line. This one pops at 2 inches of vacuum. I ordered a new one and it also pops at 2 inches of vacuum. Is this a correct reading or do I have a defective new check valve also ? The crankcase valve and the oil pump return valve get their oil from the same oil pump discharge port thru a tee. If the crankcase valve pops at 4.5 and the return at 2, it seems like all the oil would go to the pump and none to the water pump shaft. I think the return line oils the oil pump shaft itself but not sure. Thanks for any input you may have.
