657x oil in both cyls, hydro locked

[anesthes]

On a boat, if it sits for a week both cyls are full of oil and it's hydro locked.

I'm assuming rotary valve seal? Probably unlikely both crank seals went bad?

-- Joe

 

[mikidymac]

More than likely the inner crank seals are bad.

Temporary solution is to put a valve on the 12mm oil lines to the rotary gear bath, not the one to the oil pump.

 

[anesthes]

Like a shut off when sitting? I'll probably just rebuild the engine over the winter. I have a few 717s, I think I'll swap one in for now. I've never seen one of these do this in 20 years of owning these things.

 

[mikidymac]

It seems to be more common in engines that sit a lot, especially with the wrong TCW-3 oil but I don't know if that's a coincidence or not.

 

[AKnarrowback]

Being up where it's cold and sleds outnumber pwc's 50 to 1 I have noticed that it's only Sea-Doos that have consistant RV crank seal failures. I have never seen an RV crank or shaft seal fail on a rotary valve sled motor.

My first guess would be the consistant high rpm's the pwc motors run at. The RV sleds started getting phased out around the time synthetic oils started arriving on the scene, so most of them spent a lot of life running mineral oil if that would effect life span of the seals.