oil problem

[scanman]

Hi

Last week I picked up some rope around the prop (Who leaves this S*#t in the water) but managed to sail back to my mooring and had to dive under the boat to remove the ofending rope, started the engine and ran for a short while and it seemed ok.

Today I pulled of the mooring and opened the rev's up and there was a lack off rev's and I noticed that there was oil coming from the exaused but when i lowered the rev's the oil stopped. I am lifting the boat out off the water next week but have any off you good fellows any clue as to the problem.

your's chris.

 

[kgi]

Are you sure its oil and not very heavy soot deposits, when this happened to me the engine was put under such a high load that the exhaust sooted up

 

[airbubble]

looks to me there is still something around the shaft/prop. This prevents the engine from revving up normally and the oil u describe is indeed probably black sooting from overload.
Another dive i'm afraid

 

[Guest]

probably wsomething still round the prop. if this isnt the case, then there could be a number of probs

it could be oil getting into the combustion space past the valve guides or pistons or a gasket leak depending on engine maker. (my yanmar 2 gm doesnt have an oilway through the heads so cannot leak oil via a faulty gasket)

or it could simply be unburnt diesel because of an injector problem.

check the simplest first, and if not successful, get in an expert

 

[johnt]

ever wondered how your valves get lubricated Howard?

theres an oil feed pipe that runs up behind the starter motor..and its a prime candidate for what I think could be eletrolitic or intercrystaline corrosion, probably due to the electical field generated when you use the starter motor !

when I did a rebuild on a 2 GM 13 the pipe was eaten almost through where it was behind and in close contact with the motor!.. and there was NO RUST !