rusted Yanmar 3gm30 engine mounts

Nov 25, 2015
45
Endeavour 32 Middle River, Md
Does anyone know what the approx. cost of replacing (4) rusted Yanmar 3GM30 Engine mounts would be on a 1989 Caliber 33?
There seems to be plenty of engine compartment work-room to easily access the motor mounts.
Could I entertain doing this job myself?
Seems a leaky companionway sliding overhead hatchway has been leaking on the engine for some time.
I wonder if there is a possibility that there could be some bad wood around the stringer mounting screws as well and how one would check for that?
Thanks for your comments and advice.
 
Sep 29, 2008
1,928
Catalina 310 #185 Quantico
Replacing engine mounts is not a big deal. Easy to do yourself. You can get OEM mounts, but there are other options out there. I was very happy with these. MM-Small-65 rubber - $35.00/each + M12 height adjuster $12.00/avproductsinc.com, http://www.anti-vibration-mounts.net/MM1.pdf. These work out to be just under $50 per mount which for 4 is about the cost of one OEM mount. There are other options out there.

Make sure you fix the leaky overhead hatchway first. There could be bad wood in the stringer but we do not know from your description. Do the mounting bolts torque down tight enough, then your are probably OK.
 
  • Like
Likes: Allan12210

arf145

.
Nov 4, 2010
484
Beneteau 331 Deale, MD
A 3 cylinder will be smoother I would think, but with a 2GM Yanmar I found that using mounts other than the Yanmars resulted in a lot of vibration.
 

NYSail

.
Jan 6, 2006
3,048
Beneteau 423 Mt. Sinai, NY
I stuck with originals...... Took one out, matched the height and put back. Yes more expensive but worth it in my opinion
 

RoyS

.
Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
As to cost, my motor (similar motor) mounts, were $105 each for OEM's. Installation should be done with boat out of water as you must align shaft coupling with stern tube and motor carefully. The lag bolts may be checked by torquing as suggested by rpwillia above. Do not overdo this torquing as any lag bolt may be stripped with enough force. If any of the lag bolts are stripped you should be able to rotate the mount and drill new holes for the lag bolts. The shaft alignment is the hard part.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
i really don't think yanmar would have made these mounts they way they did without good reason......the massive rubber they put in the mounts are for isolation and support even though they are expensive compared to others..... using because of price only is not a good option in this case.....would you find the cheapest priced mounts available.... say they were for a four cylinder chevrolet and use them just because they were cheaper
 
Nov 6, 2006
9,885
Hunter 34 Mandeville Louisiana
I sprung (small pun there) for the Yanmar mounts when I re-did mine a couple of years ago. Originals had lasted almost 30 years, so I was disappointed that they cost so much but figured I'd keep the power train as designed. Yanmar mounts are very stiff fore/aft, since the boat is being shoved through them by the prop.. The port/stbd direction is very soft to absorb the "secondary" vibes which cannot be balanced out without balance shafts.. the up/down direction is between the other two in stiffness .. Looks like a fine design..
 
Nov 25, 2015
45
Endeavour 32 Middle River, Md
Ok, thanks for your replies...guess I will go with replacement Yanmar Motor Mounts.

Is replacing these motor mounts really considered a DIY repair?
If so, does anyone know how to do it?
I guess wooded wedges to lift motor, right?
What about the dreaded shaft alignment as a DIY project?
How?
Thanks for all your great comments.C33 engine.jpg 20160624_183858a.jpg 20160624_183630a.jpg