That makes more sense than what your mechanic is doing IMHO. It would make sense to require heavier motor mounts on the side that gets loaded when in operation. By doing what your mechanic is doing, I think the engine will tend to twist when in operation, since the forward end is supported more lightly than the back end—the torque on the forward end of the engine is equal to that of the torque on the back end of the engine...Besides, I think Yanmar has a bit more experience installing Yanmars than your mechanic.
06-27-2008 10:16 AM
Ok, seems to make sense since looking from front of engine the pulley rotation is clockwise, hence there's a force pushing down on port side of engine.
06-27-2008 10:09 AM
I believe so. On my engine the port side is to have 200lb rated mounts and 150 lb on the starboard side according to the Yanmar written specifications.
06-27-2008 09:51 AM
What is torque side ? Has it anything to do with the crank shaft rotation ?
06-27-2008 09:31 AM
Yanmar Engine Mount Specifications
I've recently had to replace the engine mounts on my Yanmar 4JH3e on my Sabre 402. The mechanic installed 200 lb rated mounts in the rear of the engine (toward the stern) and 150 lb at the front (bow). He says he's done it this way for 20 years because the engine weights more at it's rear than the front. The Yanmar specifcations show 200 lb on the torque side of the engine and 150 lb on the opposite side.
What's your opinion? Is it possible that the specifications differ for different engines or type of boat? I've directed him to install them according to the written specifications. The boat manufacturer concurs with the Yanmar