2005 J115PLSOR weird oil leak

[Harkonnen]

Where is that stuff possibly coming from? Fuel system is tight all the way up to carbs, floats set right (I think - manual calls for 1 1/16...1 1/8in or 17... 28 mm (sic) drop). Does not look like fresh fuel anyway; more like 2-stroke like mix that's been sitting for a while. Thoughts?

Thank y'all!

 

[That old Mercury]

Where is that stuff possibly coming from? Fuel system is tight all the way up to carbs, floats set right (I think - manual calls for 1 1/16...1 1/8in or 17... 28 mm (sic) drop). Does not look like fresh fuel anyway; more like 2-stroke like mix that's been sitting for a while. Thoughts?

Thank y'all!

My 90 hp 2 stoke did do that .
Had a epa non pressure vented plastic gas tank. It would swell up in the sunlight looked like it was about to explode over pressuring the whole fuel system causing tiny leaks everywhere.
Went to an aluminum vented tank and it quit doing it.
You will be surprised how tiny of a leak will make such a mess!
You may not see the leak because the gas evaporates but the oil wont.
Hope this help

 

[Harkonnen]

It's just that, one, there is nowhere for the stuff to come from but the crankcase (and if it does, why it is pooling in there?), and two, I can't see where it's coming from - between the powerhead and midsection?

 

[That old Mercury]

It's just that, one, there is nowhere for the stuff to come from but the crankcase (and if it does, why it is pooling in there?), and two, I can't see where it's coming from - between the powerhead and midsection?

Hi
You can get some fuel dye and uv light and glasses and run it on a smaller gas tank awhile and let it sit a few days then check it at night.
May have to leave it a week or more before you see something.
You can put some in your oil tank also and stir it up good.
You will see exactly where its coming from.

 

[That old Mercury]

Hi
You can get some fuel dye and uv light and glasses and run it on a smaller gas tank awhile and let it sit a few days then check it at night.
May have to leave it a week or more before you see something.
You can put some in your oil tank also and stir it up good.
You will see exactly where its coming from.

Get the oil and gas dye if you put some in your oil tank.
Sorry left that out

 

[Chris1956]

When you tilt up a carb motor, fuel often leaks. The gasoline tends to evaporite, leaving thin oil. Is that the scenario?

 

[Harkonnen]

When you tilt up a carb motor, fuel often leaks. The gasoline tends to evaporite, leaving thin oil. Is that the scenario?

It does feel like half-evaporated 2-stroke mix. Except that it almost looks like it's coming out of the bottom of the crank - everything above the exhaust housing spacer is nice and dry. Combined with the fact that I see more oil/fuel in exhaust than I am comfortable with, I wonder if fuel pools at the bottom of the crankcase, and once it fills to a certain point, it gets blown past the seal. Now, what would make it pool like that? Starts/runs OK, carbs cleaned, gaskets replaced, floats/idle screws set to factory specs. Some smoke, but nothing unacceptable for a 2-stroke (now that I replaced reeds). Problem with oil recirculation?

Either that, or bottom crank seal is messed up - which would be odd for a reman powerhead with only 6 hours on it.

Other ideas?

Thanks!

 

[saltchuckmatt]

If that crank seal was bad you'd have running issues.

I think you need to go run that motor hard somewhere. Burn it out.

 

[Harkonnen]

If that crank seal was bad you'd have running issues.

I think you need to go run that motor hard somewhere. Burn it out.

Fair enough, I was keeping it under 3K per break-in instructions. I do suspect I have excessive crankcase pressure issues, because recirc hose kept popping off

 

[racerone]

Excessive crankcase pressure is not possible !

 

[saltchuckmatt]

Fair enough, I was keeping it under 3K per break-in instructions. I do suspect I have excessive crankcase pressure issues, because recirc hose kept popping off

You need those special nylon ties....the ones that are more rounded. It won't come off again.

I'm pretty sure Racer mentioned that.

 

[Chris1956]

Maybe the Pulse Limiter is leaking. It is very low on the block.

 

[Harkonnen]

Excessive crankcase pressure is not possible !

It IS, if it (partially) fills with liquid.

 

[Harkonnen]

You need those special nylon ties....the ones that are more rounded. It won't come off again.

I'm pretty sure Racer mentioned that.

I'd rather have it come off than have the crank seal blown.

 

[Harkonnen]

Maybe the Pulse Limiter is leaking. It is very low on the block.

Probably not, the block is clean all the way down. The seal and driveshaft are right there, and there seems to be just enough of an opening for the spinning shaft to sling gunk around.

 

[racerone]

It should be easy to find this leak in my opinion.-----But I can not touch this motor.