Yanmar YSM12 Parts Crossover

[Bestathook]

I have a siezed Yanmar YSM12 in my boat. I want to rebuild it, and am trying to line up a source for parts before I begin the job. I am pretty sure I will need new rings and a cylinder sleeve, and bearings, as well as gaskets, and then some. Yanmar dealers I have spoken to tell me that parts are no longer available through them.

Has anybody had experience using parts from any other Yanmar motors to fit a YSM12? A friend suggested a YSB might cross over. I know Yanmar made a lot of agricultural diesels, and perhaps my engine was sold for agricultural machinery under a different name.

Also, those who have had a YSM12, how badly does this engine vibrate in use? Is there any other significant pros or cons to this model?

I have found the Boy Scouts' manual and a little bit more on the net, but I am pretty much in the dark on this Yanmar, and any information will be appreciated.

[SunnyJ]

Any luck with your YSM12 Bestahook?

Cheers

Bob

[Bestathook]

Not yet, but I have too many other projects to work on it much.

[Compass790]

Try toadmarinesupply.com. You might have to have a friend in one of the states that they ship to as yanmar ties their dealers up in an area agreement but check it out. I'm in New Zealand & I got the parts shipped to Michigan first & then to NZ. They will get parts from japan for you with a 3 week delay. I got injection pump bits from them. You can still get most bits. I have a YSM8 which is largely the same & it was given a new liner, piston & rings & the gaskets by the former owner in 2012.
I recommend the workshop manual as it's pretty comprehensive although does not have part nos. I might be able to send you a parts list if I can figure out how or a link to one if you need that.
Regards Paul

[SunnyJ]

Awesome Paul

I am only about 6 hours north of toadmarinesupply. My YSM12 still
thumps like a lion. I think that iron-genny is the beesnees. My boat is a
C&C 27 MKIII and the little Yanmar seems like a match made in heaven. Maybe I'll give them a call and see if I can get the parts for a
future overhaul.

Thanks very much Paul.

Bob

[Compass790]

A few more things that I should pass on about the YSM. Our YSM8 vibrates a lot but it's not alone in that as single diesels do in my experience ( Lister 6.5hp, farymann 10hp ) You have to be sure the anode in the engine has been replaced regularly as if they get too corroded they are not worth rebulding as they are prone to cracking.
I see on Ebay they have a brand new 13.4hp Yanmar twin for $850 + shipping that if you are mechanically inclined would be worth fitting with a heat exchanger & sorting out the engine mounts & marrying up to your YSM 12 g/box. You would end up with a smoother quieter & probably more fuel efficient motor. Depends on your mechanical knowledge tho, would be very expensive to pay a mechanic to sort all that out. If I lived in the U.S. I'd be tempted to go that route rather than rebuilding the YSM12 especially if it has high hours or is badly corroded. There is another thread somewhere concerning that 13.4hp Yanmar.
Just some things to think over

[SunnyJ]

Thanks again Paul. Will check out the twin. Still like that YSM12. Has a 1939 BMW R71 once. Cheers

[rumiko dan]

Bob,
I have pulled my YSM12 out, we are going electric.....
It ran last time we tried, but did blow smoke. We have a decent collection of gaskets, etc new in original bags, and could part out engine (or you could have the whole thing, but we are in Colorado). I will try and get a list and pictures together.

Dan

[SunnyJ]

Hi Dan......Thanks for contact....PM inbound. Bob