Motor Mounts

This post addressed some puzzles that go back as long as 20 years. It may also help some amateur mechanic as naive as I was.

“Be sure and tighten up these motor mounts often.” said mechanic Al Blande as he was finishing up the 50 hour service on White Pepper's new Yanmar engine.

The motor mounts are huge 15/16 inch bolts mounted on shock absorbers. They were indeed loose after only 50 hours of use. I had never tightened the motor mounts on the old engine, a 3HM. I guess I thought that they tightened themselves magically. Actually I never gave the motor mounts a thought until they broke.

White Pepper had broken the motor mounts on two previous occasions. One time was about 20 years ago motoring up from Brownsville. Only one mount broke with little damage. Another time was about 12 years ago. Three of the mounts had broken at the same time. The motor fell into the bilge pan but kept turning. The aft part of the transmission was bent and there was considerable damage. I had carelessly assumed that the problems was electrolysis since electrolysis was the cause of almost all my problems at the “hot” pier at the Corpus Christi Marina. Now I was forced to consider that shock loading was the culprit. Maybe loose motor mounts had damaged the old motor and threatened the new engine.

I bought a large15/16 inch box wrench and tightened three of the four mounts. But I could not reach the forward port mount no matter how I twisted and stretched. The new motor just barely fit into the engine compartment. There was simply no room for 12 inch box wrench. I bought a 15/16 socket but could not find a driver that would fit into the space available.

Vero Beach friend Davido from s/v Utopia came to the rescue. Davido is a “tool” guy with a vast array of tools and wrenches from a lifetime of collecting these things. He brought over a “half moon” wrench, a 90 degree wrench with a short handle, and a 12 point box wrench with a 6 inch handle all in 15/16 size. By successively using each of these several times over he got the mount very tight.

Thanks, Davido! But now I will have to figure out how to do this myself.