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openseas · 18-06-2014, 11:23

Hi all,
I have an inboard Yanmar diesel engine 15hp (2QM15) that is almost 30 years old. When it runs, it is very noisy ( compared to other sailboats), sounds like knocking sounds.
I took some pictures of the engine, and when I was looking at them on the monitor, I noticed that the engine has no motor mounts.
Shouldn't Yanmar engines have motor mounts like cars or what?
And my next question, if the engine was missing the mounts, and I wanted to add them, do I have to disconnect the shaft drive from the engine, to be able to lift the engine?
Thanks,

Andy

Enclosed is a picture.

model 10 · 18-06-2014, 11:57

It looks like it has mounts, the same style mount as on my Perkins 107. It's a little hard to tell with the rust, stains etc..

**a64pilot** · 18-06-2014, 12:02

It has mounts, the noise could be injection pump out of time, or dirty injectors.
Could be other things, but I'm trying to think good thoughts here

HBWT · 18-06-2014, 12:57

Yes those are your engine mounts in the picture. They more than likely bolt through a steel plate mount, through a rubber vibration mount into a recessed threaded female bolt that is glassed into the hull. The loud knocking is definitely more likely your injection pump or even more prevalent on older Yanmars is carbon build up and misspray from the diesel injectors. This would make your piston fire incorrectly and create that loud knocking and vibration. I would have a Yanmar mechanic come and check it out. Another way to do a basic troubleshoot is to fire up the engine and if you have white or black smoke coming out and/or a sheen of diesel on the water surface next to your wet exhaust, you probably have an injector problem. The good news is the cost to fix is relatively inexpensive, I think the last time I checked on our Yanmar it was $62.00 to replace the ejector needle valves or $50 per injector to have rebuilt. Good luck and keep us posted on the problem and solution.