Fuel Leaking From Power Head

Where is the fuel pump located?

I think I remember a old Evinrude we used to have had the fuel pump fittet on the crank case.

If it's runn by the crank or preshure in the crankcase a gasket in the fuel pump esambly could be leaking. It's the only thing I can think off at the moment.

 

This is an oil fuel mix, not oil injected

 

The thing is that if it wasnt for a fuel leak we wouldnt even be talking about it.

As I understand it the engine runs perfectly exept for a fuel dribble if you look for it.

Fuel is not supposed to come out of the bottom bearing cap.

All I can suggest is to look agaim at the bearing cay very carefully -clean clean. There could be elecrolisis or some crack.

But even then there should not be so much liquid fuel in the botton of the crank case.

Stian has a good idea but that would have shown up on the static bulb pump up test.

If it were mine Ide have the cap off again.

Try to pinpoint exactly where its leaking --gasket--seal --bolt head

 

The fuel is leaking past the O-Ring seal then seeping from around the flange of the bearing cup (see parts diagram from previous reply) then collecting on the bolt heads then dripping off. The hole for the bolts do not go all the way through into the crankcase so there is no way fuel can touch the bolts except as I just described.

 

The fuel is leaking past the O-Ring seal then seeping from around the flange of the bearing cup (see parts diagram from previous reply) then collecting on the bolt heads then dripping off. The hole for the bolts do not go all the way through into the crankcase so there is no way fuel can touch the bolts except as I just described.

 

It sounds as though you may have got some bolts mixed up with the power head and they are bottoming out check lengths of bolts carefully. Clean out the holes with a dentists pick or similar. Clean clean clean.

If the o ring is failing then this is your problem.

 

I thought of that, correct bolts, correct lenght, and replaced the O-Ring with a new one but same problem, still leaks..... I think I can get a "For Sale" sign pretty cheap.... LOL

 

Well thats an easy way out especially as we have it nailed.

Are you sure the o ring is the right one.

I mean we are nearly there. Is there corrosion on the mating surface. Put a bit of gasket goo on it.

Dont overtighten the bolts or you will need that sign.

 

O-RIng is correct, bought it a OMC Outboard service center, the part # is the correct Part # from BRP.

 

Have you checked the cap for distortion. Get some plate glass and some 600grit wet and dry. Check to see if you havnt bured the edge of the plate so it doesnt sit.

When the plate mates to the block there should be no feel of metal to metal contact while turning by hand. You should only be able to fell the rubber o ring.

 

Or dblanton face the cap face down on a sheet of glass with the o ring in place and check with a feeler guage for an even gap all the way round. At a guess it should be about 7thou ish

 

The groove that the O-Ring goes in is wide enough to install two O-Rings, I am going to try that as well as make a gasket for the flange on the bearing cap with some RTV sealer

 

Oh Oh theres something wrong there then. With an 81 engine (i think you said) all sorts of mods could have been done by people who know better.

Take the plate to a spares shop and get a ring that fits your groove . I would be reluctant to use a gasket as you are now in effect making the gap between the crank bearing at the top and the bearing at the bottom bigger.

 

I have talked to two OMC Master Tech's one with 30 years of experience, and both have told me to reseal the crankcase halves.I pulled the power head off and I am ready to separate the two halves but before I remove the bolts to separate the halves I was curious if the power head had to be in any certain position, I have the power head sitting on my work bench in the same position as it would be when it is mounted to the leg on the boat, is it ok to separate the halves in this position? I know to some this may sound like a stupid question but I just want to be sure that the crankshaft won't drop down or out pulling the pistons down to low.
My manual doesn’t say any thing about what position the power head should be in but it does give detailed instructions on how to separate the halves.

 

I got it fixed, I resealed the crankcase halves and that did the trick.