oil in combustion chambers

[SEA DOO 94]

I have a 1994 seadoo spi with the white 587 motor. The engine was rebuilt, less than 10 hours of use. It has a new crank, pistons and was bored 1.00 mm over. When I store it for long periods of time it seeps oil into the combustion chambers causing difficulties in starting and heavy smoke discharge. I was told that this was due to faulty crankshaft seals, but I cant see how because its a new seadoo crank? I have only used rotax oil in it and it has the stock oil injection pump on it. Would converting to pre-mix help this problem or would it be a waste?

[Technical Support]

The dignosis is correct. If the seals were new and in good condition, it's probably an assembly error. It's critical to get the case surfaces and seals perfectly in the grooves, and use the correct sealers or you can get leaks. Unfortunately it means you need to at least pull your engine, tear it down and take a look. You *may* be able to clean everything up and resela it, if the selas aren't damaged or misformed. What did you use to seal the cases and seals?

[SEA DOO 94]

I had a shop do it for me, it looks like they used loctite gel- seal around the case halfs but thats all I can see without tearing it down. I was also told that the inner crank seals were not serviceable due to the fact that the crank is pressed together. In your opinion, do you think that its the inner seals causing this leak? At this point would it just be better for me to look into a remanufactured engine, than to have it torn back down and resealed or face the possibility of having to install another crank? I dont have any warranty on this engine and I am tired of wasting my money. Thanks for the reply and help.

[Technical Support]

Well, a new engine would certainly be easier, but it is significantly more than just doing a crank. Yes it's true you cannot change the inner seals alone.

[SEA DOO 94]

Okay I removed the engine and have decided to just get a SBT crate motor. What all do the engines come with? Do they have all the gaskets for the installation? Also, do you think it would be good to get a block off plate to disable the oil injection? If I do remove it, how does the ski react to it as far as idle and smoking are concerned? Thanks for your help.

[Technical Support]

If you block off the ski will smoke more at idle, but not perform any differently.

We have Installation Gasket kits for $30 for that ski.

[Bill O'Neal2]

Didn't anybody ever try to check the seals by using a pressure tester before you decide to replace the engine? Block one fitting and pressurize the other. See if it holds 5 lbs of pressure for a few minutes.

How much oil are you talking about? Does it ooze out the exhaust in the rear? Does it froth out of the sparkplug hole when you crank the motor using the starter?

[SEA DOO 94]

Its enough oil to hydrolock the engine on start-up. When I pulled the exhaust manifold off it poured out the cyl. ports. Plus, its leaking out from somewhere on the case into the bilge area. What are the other causes for this condition? Thanks for your help Bill, and i will look into pressure testing it this week.

[Technical Support]

Don't bother, it's shot.

[Bill O'Neal]

I agree. The seals are leaking badly. I thought maybe you were talking about some small amount oil in the chambers.

[SEA DOO 94]

Bill, what are some things I should go ahead and do to the pump while its off. I know I should change the pump oil, but what about the wear ring, seals and bearings. I have replaced the carrier bearings and fiberglassed a new carrier in the hull so I know those are good. Also should I go ahead and get a new rotary valve and cover as mine has some grooves on it. There not deep and I can hardly feel them with my finger nail. Thanks SBT and Bill for all of your help.

[SEA DOO 94]

Oh and what size nut is it on the flywheel, I did not see it listed on the tool list on the engine install guide. Thanks

[Technical Support]

I believe it's a 24mm...

[SEA DOO 94]

Well I checked with my local dealer and he pressure tested the crank seals and said they were good. So I guess either the oil pump is bad or the rotary valve shaft seal is bad? He said that there is a check valve in the oil pump that will fail and let oil seep into the cylinder area. Whats your take on his dignosis?

[Technical Support]

The seal leaks often do not show up on a pressure test. I have had them not leak for 2 weeks on a test stand here. Pinch the oil feed line to the pump to test his theory - but you will need to let it sit for a week or more to see.