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2003 90 h.p. 2 stroke Model #1090412AD hard starting, smokes

Diesel Pusher

New member
Seems to be getting too much oil, fouls out plugs on start up. Once you get going faster, it seems to run okay, but seems to use more oil than it should. Oil pump is located under fuel pump on port side. Small line coming from oil pump to fuel line has brass fitting connected to fuel line. Is there an adjustment on the oil pump (I couldn't see one) or could a defective fitting or defective oil pump be letting too much oil pass through? It is a 2003 90 h.p. Mercury with oil injection. Thanks for any help!
 
That brass fitting is a check valve allowing oil to enter the fuel line but keep fuel from backing up the oil line....like would happen when you prime the engine with the squeeze bulb.

The service manual tells you how to check oil flow. Get a manual.

If you crank the engine the oil pump adds oil to the gasl just as happens when the engine is running. If the engine doesn't start, or is slow to start, that oil is in the cylinders and has to have time to burn off as the oil pump only puts out a 1 part oil to 80 parts gas at low rpms, coming up to 1 part oil to 50 parts gas at the higher rpms.

Solution is to tune up your engine to get faster starts. Another thing that may help in a faster start is to tilt the engine up in the rear 10-15*. This keeps oil from puddling at the rear where the plugs are and aids in faster starts.
 
How long have you owned this motor? Are you sure it is not flooding from fuel? May just be the check valve in the line is bad. If you have to tilt the motor up to start it there is something wrong with your motor.
 
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