I have a 1983 5411 (M-15) Universal Diesel that tends to vibrate a bit at high speed under load. I've had a mechanic realign the engine and that helped a little but he says unless the engine mounts are replaced no further alignment adjustments can be made. Has anyone here done an engine mount replacement on this engine? Can just the rubber cushions in the mounts be replaced? Do you have to pull out the engine to do the job or can you somehow replace the mounts one at a time with the engine still basically in place? (And then, of course, realign the engine.) Thanks in advance for any info on this kind of project.
The rubber part of the mount is bonded to the steel parts with the stud attached. You will need to replace the complete mount.
Once they get old, and "old" means over 15 or 20 years, the rubber can compress down and collapse, and if not that it will harden from aging of the rubber compound and lose its ability to attenuate vibration. Depending on the installation, some engine installations will have allowed sea water to attack the steel or fuel oil to attack the rubber.
Buy new mounts as a set. Your Ericson will likely need three if the Universal has the single front mount. Note that, depending on the balance point of the engine, the weight specification may be different for the real mounts than for the front.
I replaced all of our mounts (M25XP Universal) a few years ago when I looked really closely and found that one on our rear mounts was collapsed down to where metal was bearing on metal. Hard to see with the typical small-boat engine installation where you might need a mirror-on-a-stick to even see it closely.
Our mounts were replaced without pulling the engine. Usually the engine can be raised up, one side at a time, and the new mount slipped in. Check to see if the lag screws into the frp mountings will still allow you to torque 'em up tight. We find that even with relatively
good access on our boat, it takes several different wrenches and sockets and precision swear words to do this job.
New mounts can be sourced from Univeral/Westerbeke or from independant sources like PYI.
Please also report on your questions, answers, and progress over at the owners' site at EricsonYachts.org: The Starting Point on Ericson Yachts!
. Pictures are a great help.