Crankshaft Seal

[SE_FL_Bassaddict]

I have a 2003 150HP Yamaha Vmax Carbed that I recently changed the impeller on and when I pulled the LU off to do the job I noticed the shaft was oily. Most likely it is a crankshaft seal, right?

What is a reasonable cost to replace the seal and is it alright to keep using the outboard in the mean time? I was told that I can get water in the cylinders by one mechanic and that I should fix it immediately, another said that if the crankshaft is dirty/oily next year when I change my impeller to just do it then, and water intrusion is not likely.

[ChrisH]

the shaft should have a light coat of grease on it.

[taeheel2az]

One way to go is to routinely check the LU lubricant. Easy to do, take out just the lower plug and let out a dab oil.

[Rich Z]

If you are absolutely certain that the oil on the shaft is the same oil you use for your motor then I would NOT use the outboard until that seal is replaced. You should be able to see a small part of the shaft entering the power head near the steering pin under the motor pan to confirm the leak while motor is running on a hose. If oil is leaking from that seal then most likely water can get into the motor. There is a seal cap on the bottom of the power head. Power head must be removed, seal cap taken off and new o-ring and crank seal replaced. I’d say about 3-4 hours of labor and parts, including a new power head gasket.

[hooken203]

There is no oil in the crankcase on a two stroke except what comes in with the fuel. If that lower crank seal was leaking it will cause a vacuum leak which can cause the bottom two cylinders to run lean and possibly burn pistons. I doubt that the crank seal is leaking.

[Pacer]

2 stroke oil can leak from the bottom seal. I changed the seal on my 225 HPDI. It started leaking after a rebuild. Only takes a couple of hours. You will need the powerhead gasket, the seal, and the O-ring. And a shop hoist.

[Rich Z]

Yep, there is always oil on that seal. The end cap even has a bleed off groove where one of the oil lines connects to on the bottom of the block. The end cap must be put back lighned up with bleed off passage in the block. It maybe on the wrong way now and thats why its leaking.