Black/carbon spark plugs and oil in Hull

[97gts717]

Hello all, I recently got my first ski after being an avid snowmobile for years.


When I was checking out the ski I noticed that there was a decent amount of oil in the bottom of the hull, on both sides, but more on the exhaust side. I had figured that this could be due to a cracked or bad oil line. To add to this, the spark plugs were almost caked with carbon, which I assume is from too much oil. Is this due to crank seals and or rotary valve seals? I haven’t even had it out on the water yet but I am curious if it will be okay to drive on the lakes as I’m sure the previous owner did for years.

The previous owner ran it on the lake for me and it sounded great and appeared to have ran perfectly, I did notice a strong scent of burnt oil but hey 2 stroke was in the air

Tomorrow I will be checking the alignment of the oil pump, but I’m positive it is connected and not in “full send” mode as I eye balled this once the day I got it. Kinda nervous about this one

 

[JeremyD615]

The crank seals fail far more often than the rotary valve seal. If it’s not loading up with oil to the point that the crankcase is full, then I’d run it until the seals fully go... You do want to go through and do all of your preventative maintenance though. Go over the fuel system, service the jet pump, and find your external oil leak. The lines do split on occasion, but the tank seams or the grommets are the usual culprit...

 

[97gts717]

The crank seals fail far more often than the rotary valve seal. If it’s not loading up with oil to the point that the crankcase is full, then I’d run it until the seals fully go... You do want to go through and do all of your preventative maintenance though. Go over the fuel system, service the jet pump, and find your external oil leak. The lines do split on occasion, but the tank seams or the grommets are the usual culprit...

Appreciate the advice, ski won’t be on the water for about a week from now, so I am currently in the process of getting the maintenance done as I am positive the previous owner didn’t keep up with.

Ironically, the other day I noticed the grommet on the oil sensor was seeping oil, as well as there was dried oil/dust on top of the tank itself(due to previous leaking). I am hoping to god this is the issue , oil seeping out of the top of the tank when ski is in use... seems entirely possible especially if previous owner didn’t care to clean out the bilge or do anybody maintence. already bought the grommet too, so should be installing that soon, guess I won’t know til she’s on the water.

 

[JeremyD615]

When the oil tanks leak, they generally do it while the ski is sitting. If you’re getting oil from the top of the tank like that, I’d suspect that the vent line is plugged and pressurizing the tank.

 

[97gts717]

When the oil tanks leak, they generally do it while the ski is sitting. If you’re getting oil from the top of the tank like that, I’d suspect that the vent line is plugged and pressurizing the tank.

That is interesting. When I first got the ski home I took out the storage cubby in the front of the ski in order to see the front side of gas tank etc. I noticed that there is a 3/32 hose that is glued closed or plugged... it is on the right side by the fuel vent if you are sitting on the ski. I have no clue if this is the line you are talking about. But I will trace it after class today

 

[97gts717]

When the oil tanks leak, they generally do it while the ski is sitting. If you’re getting oil from the top of the tank like that, I’d suspect that the vent line is plugged and pressurizing the tank.

After some quick research, this vent is right above the oil sensor, which I will check as well