Any outboard motor experts out there?

[Quickstep192]

I have an 8hp Honda 4 stroke for a kicker motor. I recently replaced the impeller, thermostat (required removing the intake manifold), rebuilt the fuel pump and adjusted the valves. Since I put it back on the boat, I notice an oily slick on the water when it's running. If I rev it a little, I'll also notice little white balls that float to the surface then burst at the surface adding to the slick. All of this is with the motor in neutral. This may have been going on for a while and I'm just now noticing because I'm paying closer attention after the work I did. I don't think any of the parts I took apart are areas where oil and water could co-mingle if I put something together wrong, but I'm not sure and that's why I'm posting. I've checked the crankcase oil level and it doesn't seem to be dropping. I also changed the oil to check for water and there's no water in the oil. I ran it for 2-3 hours over the weekend with no problem and it runs well except for the oily slick. I don't see any leaks around the power head. Any ideas?

[Cruisingdad]

Wow. Oil was my first thought. Crap, if you've done all that you know more about your outboards than I do. I just swear at mine and go buy a new one when I need a new anchor!!

Have you recently checked the oil to see if water is getting back into it? Maybe oil through the exhaust? Keeping an eye on your oil level? Maybe it is only residual oil/gas from work you did (like not setting the motor with the tiller down when laying it down)?

Just throwing out some ideas. Curious what you find out.

Brian

[Jurgy]

Any chance mixed gasoline was put into the tank ??

[mdbee]

What year motor? I have a 1991, that impeller is a pain to change.

Have you checked your lower unit to see if water has gotten into it? The 90wt would be white.

I haven't replaced my thermostat but is there only water and a fuel intake track there, no oil?

No oil blowing out the exhaust vents/holes, down by the prop?

Originally Posted by Quickstep192

I have an 8hp Honda 4 stroke for a kicker motor. I recently replaced the impeller, thermostat (required removing the intake manifold), rebuilt the fuel pump and adjusted the valves. Since I put it back on the boat, I notice an oily slick on the water when it's running. If I rev it a little, I'll also notice little white balls that float to the surface then burst at the surface adding to the slick. All of this is with the motor in neutral. This may have been going on for a while and I'm just now noticing because I'm paying closer attention after the work I did. I don't think any of the parts I took apart are areas where oil and water could co-mingle if I put something together wrong, but I'm not sure and that's why I'm posting. I've checked the crankcase oil level and it doesn't seem to be dropping. I also changed the oil to check for water and there's no water in the oil. I ran it for 2-3 hours over the weekend with no problem and it runs well except for the oily slick. I don't see any leaks around the power head. Any ideas?

[dabnis]

Quick,

You mentioned changing the impeller. Possibly the shaft seal may
have been disturbed? Suggest you drain the lower unit gear lube
and see if it is milky, murky, discolored or anything but clear clean
gear oil. The only other source I can think of is crankcase oil leaking
into the water discharge or exhaust passages? If it was from the
combustion chamber the exhaust would probably smoke.

Dabnis

[casioqv]

There's only three hydrocarbons in an outboard in sufficient quantities to cause a slick- crankcase oil, lower unit oil, and gasoline.

If your crankcase oil is clean, and full- you're either leaking gasoline or lower unit oil.

[casioqv]

I suppose if it's just a light sheen in neutral, it could also be from extra lubrication grease on the driveshaft, but this should wash away pretty quickly and stop.

[docon48]

I had a similar problem with my 1996 8HP honda. It seems the carburator float was getting stuck and gasoline was leaking out of the small vent on top. I took the carburator apart and cleaned everything thoroughly with carb cleaner. A few new 'o'rings and it was good to go. No more sheen and motor runs much smoother.

[dabnis]

Originally Posted by docon48

I had a similar problem with my 1996 8HP honda. It seems the carburator float was getting stuck and gasoline was leaking out of the small vent on top. I took the carburator apart and cleaned everything thoroughly with carb cleaner. A few new 'o'rings and it was good to go. No more sheen and motor runs much smoother.

Wondering if you also saw the little white balls that burst when surfacing?
Not sure that gasoline would do that? My guess is that it is either
crankcase or gear oil?

Dabnis

[docon48]

Originally Posted by dabnis

Wondering if you also saw the little white balls that burst when surfacing?
Not sure that gasoline would do that? My guess is that it is either
crankcase or gear oil?

Dabnis

I did not noticethe little white balls, just a sheen.