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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10905
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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I have a 1994 V4 140 outboard. It tests 125psi across all

Customer Question

I have a 1994 Johnson V4 140 outboard. It tests 125psi across all cylinders. new plugs and wires. It seem to be using a lot of oil. the exhaust is quite blue. I believe it to be the VRO pump. Is there a diagnosis for the fuel/oil pump?
Submitted: 1 year ago.
Category: Boat
Expert:  Tan replied 1 year ago.

Hello. My name is Tan.

There is no adjustment for the VRO oiling side. Now what causes the VRO to over oil is the VRO pump sucking air on the fuel side this makes the pump cycle faster pumping more oil. We need to check all the fuel line connections be sure they are tight. If any of the fuel lines are hard they will not seal very good.

Here is the test for the VRO pump. This is for the fuel pump side.

Here is the test for the oil side of the pump.

Post back with questions. These checks and tests should lead to a resolution.

If you still have an issue you can always post back with findings and questions.

Thank you......Tan

Customer: replied 1 year ago.
Do i have to check the lines all the way back to the tank mounted under the floor?
this might take me a couple days to get back to you
Expert:  Tan replied 1 year ago.

Yes anyplace it can suck air. Take as much time as you need. I'll be here.

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