We're having some issues with a 1977 Yanmar
. There are some wisps of smoke from the engine
between the exhaust elbow
and the fuel
injector. Assuming this was an issue with either back pressure due to build up in the elbow
and/or a worn out gasket
between the elbow and the engine
, we removed and cleaned the exhaust
and mixing elbows (they re now totally open) and re-installed them with a new gasket
, but the wisps of smoke remain.
As troubling, this season the engine has also been running rough and missing a bit at idle and there is excessive white smoke coming out of the exhaust and a fair amount of black, oily soot appearing on the water
and the transom. Assuming that the 2 year old fuel
had gone bad, I pumped it out and replaced it with new, but the white smoke remains. I've tried to read up on what may be the cause, but dealing with this appears to be above my pay grade. Two possible issues suggested to me are:
1) Fuel injected into the cylinder is not burning correctly possibly due to:
* Engine/pump timing out
* Fuel starvation to the pump causing the pumps timing not to operate correctly
* Low engine compression/Partially engaged decompression lever
* Water/petrol in the fuel
leaking into the cylinder possibly due to a head
gasket leak or even a crack in the head
The fuel injector was replaced last year, the head gasket was replaced 8 years ago, she starts quite quickly (assuming that means decent compression), and the fuel is now new. The only obvious thing to me is a bit of a translucent mass around the drain plug
of the primary Racor
filter. I'm not sure if some sort of growth in the old fuel has partially plugged up the several month old filter and if this could be causing the white smoke or if there is some other explanation that would account for white smoke as well as the wisps of smoke from the engine.
]Any ideas would be greatly appreciated.