Yanmar YSE8 trouble

[Pikor]

Had a bad day yesterday. We hit a big patch of dense algae in Southampton Water. Propeller got caught and engine slowed down then stopped. I've managed to start it again, put it in reverse and clear some stuff from the propeller. However, for some time afterwards the sound wasn't pretty and it did spit some black gunk. We had no choice but to motor home without wind and against the current. Engine sounds OK but it has very low oil level (pressure still OK). And we were going slower than expected (hard to say for sure -log died - bad day).

I am planning to refill engine oil and dive to check how it looks underneath. But I wonder if someone had a similar experience and can share? I think in those old Yanmars engine and clutch have common oil flow.

 

[coopec]

I don't know anything about the Yanmar motor. But just reading:

I think you got some bad advice. I have a YSM8, which I think is similar, and I have to drain from both locations, and fill from both. A manual I found says:
"Although the crank chamber is not connected with the clutch case, the same lubrication oil is employed for both"
meaning the same type of oil is used for both.
If you want a copy of my manual, let me know. It's about 20MB pdf, but I have it broken up into sections too.

Kevin

https://forums.sailboatowners.com/index.php?threads/yanmar-yse8-oil-change-fill-question.120035/

Yanmar YSE-8 | Boat Design Net
https://www.boatdesign.net › ... › Design › Propulsion › Diesel Engines

Feb 15, 2007 - 3 posts - ‎2 authors
I acquired a Yanmar YSE-8 some years ago and am just now ... Anyway, it says change motor oil every 100 h and gearbox oil every 250 h.

 

[Pikor]

Thanks @coopec, but I think this is incorrect. I just checked the manual and the engine (it is a new boat for me). There is also a flow diagram in the service manual. I am convinced that engine and clutch oil are common and gearbox oil is separate. There is one plug at the gearbox and one at the engine.

 

[coopec]

OK right.

(That doesn't conflict with what the other guy is saying as I understand it)

 

[RobW]

..worth checking your seawater intake strainer if you have not done so already., just to make sure things are cooling properly - sounds like your engine has been working hard.

Other than that - as you say - top up the oil and check the prop and stern gear are clear.

Good luck!

 

[Spyro]

Is it running fine out of gear? Can you turn the shaft freely by hand?

 

[Pikor]

Is it running fine out of gear? Can you turn the shaft freely by hand?

I don't know, hard to reach and I am now out of the boat. I will check.

 

[oldharry]

Is it running fine out of gear? Can you turn the shaft freely by hand?

+1, sounds as though you may still have stuff very tightly wound between the prop and the end of the shaft bearing housing absorbing much of the power. Not always obvious except on close examination, and often pulled so tight it can effectively be a solid mass which is difficult to cut away, particularly if it is plastic based.

 

[superheat6k]

I installed a YSE8 on my last sailing boat, and it was just fine until the day I came to sell it when whilst on sea trial it decided to start running on its own oil - never seen a diesel go so fast - nearly had the 26' Van De Stadt planing !

Then the head gasket blew with a very Big Bang filled the cabin with oily smoke and the engine finally stopped.

The would be buyer still went through with the deal, as long as I fixed the engine. I also threw in the Yamaha 8HP longshaft on the transom for goodwill though.

Not sure I would fit another old Yanmar YSE8 as I am sure the horizontal cylinder increased its propensity to run on its own oil !

 

[coopec]

I installed a YSE8 on my last sailing boat, and it was just fine until the day I came to sell it when whilst on sea trial it decided to start running on its own oil - never seen a diesel go so fast - nearly had the 26' Van De Stadt planing !

Then the head gasket blew with a very Big Bang filled the cabin with oily smoke and the engine finally stopped.

That is priceless!! I'd love to have been a fly on the wall when that was happening!