BoatBanter.com - View Single Post - Aligning engine to shaft(13 hp yanmar 2gmf on sailboat)

Richard Casady

On Sun, 19 Oct 2008 09:10:42 -0700 (PDT),
wrote:

Years ago when I installed this diesel in my sailboat, I read about
aligning the engine output shaft with the prop shaft by using a valve
clearance guage to check all round the round pieces that bolt the two
together. One would tighten or loosen the engine mounts to make it
the same all round. I can no longer find these directions and am
having problems getting it just right. One side is off by .008" and
all I can think of is slightly rotating the engine (about a vertical
axis) by pushing against the engine mounts but this doesnt sound
right. Thoughts?

Loosening engine mounts is probably not a good idea unless they
designed it to be adjusted. For openers an ordinary nut needs to be
tight enough to keep it in place. I realize there are ways to combat
that. If loose, vibration will beat metal against metal, with,
possibly, rapid wear. I think they usually use steel shims.
Better yet, a U-joint. They are not unheard of on boats, the family
runabout has one. Driveshaft from engine to jet pump looks like it
came off a car. One from a car's steering column might be sturdy
enough handle the torque. I don't know why they don't use them on
boats.

Casady