White smoke and fuel smell 115 Merc 4 stroke

buzzlghtyr

Recruit
Joined
May 26, 2011
Messages
4
My 2007 115 Mercury 4 stroke efi outboard is emitting white smoke and what appears to be fuel coming out of the propeller area. The oil also smells of fuel.
Thanks for the help!
 

Bartine

Petty Officer 3rd Class
Joined
Jun 18, 2008
Messages
78
Re: White smoke and fuel smell 115 Merc 4 stroke

Could be a lot of things and there are people here much smarter than me, but it could be the fuel pump leaking fuel into the oil or a leaky injector. How does the motor run, how full is the oil?
 

buzzlghtyr

Recruit
Joined
May 26, 2011
Messages
4
Re: White smoke and fuel smell 115 Merc 4 stroke

Could be a lot of things and there are people here much smarter than me, but it could be the fuel pump leaking fuel into the oil or a leaky injector. How does the motor run, how full is the oil?

The motor runs rough and the oil level is past the full level after running.
Thanks for your help!
 

dunc333

Seaman
Joined
Dec 27, 2009
Messages
54
Re: White smoke and fuel smell 115 Merc 4 stroke

if i were you i would do compression test on all cylinders and a leak down test ,hopefully for you it might be a leaking head gasket or leaking manuel fuel pump diaphram good luck and let us no how you get on cheers dunc333 in australia
 

Wingedwheel

Lieutenant Junior Grade
Joined
Jun 16, 2009
Messages
1,071
Re: White smoke and fuel smell 115 Merc 4 stroke

I'm also thinking a head gasket as the oil level would change due to water leaking into the cylinders. Also white smoke is generally and indicator of water vapor mixed in with the exhaust on a 4-stroke.
 
Joined
Oct 28, 2010
Messages
923
Re: White smoke and fuel smell 115 Merc 4 stroke

If you mean the oil level is rising (making oil) after running, could be as pointed out before the fuel pump that is camshaft driven is leaking into the sump or maybe your ECT sensor/thermostat (cold running engine) that is adding too much fuel. I would get a pyrometer and measure when the tsat is opening up, HF has a cheap on that works good. If the ECT sensor is bad might want to verify timing and see if timing is locked. I think this is one of those sensors that will make ECU run in base timing. It might be easier to see with diag. software.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: White smoke and fuel smell 115 Merc 4 stroke

First off, unbolt the fuel pump but do not remove the fuel lines, pump the primer bulb while watching the backside of the fuel pump for any fuel leaking. If fuel is leaking, rebuild or replace the pump, change oil and filter.
 

dunc333

Seaman
Joined
Dec 27, 2009
Messages
54
Re: White smoke and fuel smell 115 Merc 4 stroke

he is saying his oil is milky so im more leaning to water mixing with oil not fuel .
 
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