my lister boat engine is leaking diesel into the sump why?

Question

it is an air cooled three cylinder and there is deisel in the sump. what would course this, is it the rings or could it be something less serious

Answer 1

Listers have fuel pipes within the body of the engine. When these leak the fuel oil ends up in the sump .Check all unions (the ones you were getting air through last week!) and tighten an /or replace copper washers on banjos.

Answer 2

If it lacks compression on 1 cyl, then diesel could get into the sump, past the piston rings of the non firing cylinder. I am not familiar with this type of motor, but if it has injectors inside the rocker cover, then the injector pipework under the cover is most likely broken or leaking. Very common fault on smaller Mercs.

Answer 3

Wipe all the diesel off the lines & injectors. Us paper towel an start engine. Put paper towel on 1 fitting at a time you will find the leak then fix it . Have fun.Yes it serious it a $10,000 fine if pumped over board.An a big mess.USA??

Answer 4

It`s something to do with the injectors. I know this sounds daft, but it happened to my mates boat and I actually helped him to fix it, but cannot remember exactly what we did.(probably been in the club too long)
The sump was filling up with diesel.
I know we took off the cowling around the engine and took out the injectors.
The good news is it only took a couple of hours and didn`t cost much.
This may sound like the rambling of burbling idiot, but hope it points you in the right direction
Good luck and happy cruising.

Answer 5

Havs you checked the feed lines,,,lift pump,,,and all joints and seals ?

Answer 6

its the rings.check rocker box for signs of white foam could be head gasket