Yanmar 2GM20 Vibrating . . .

[reiner]

My Yanmar 2GM20F is vibrating above 1800rpm. My guess is that I should have a look at the motor mounts but I don'y know how much they vibrate anyway.
I realise that 2 cylinder diesel motors have to vibrate a bit but mine feels a bit much.
Any other suggestions out there on where to look???

[Drumroll30]

Definitely check your motor mounts, your prop shaft is likely out of alignment. Also check that your prop isn't fouled.

[sandy daugherty]

Get you eye as close as possible, thoroughly clean off each mount and have someone move the engine side to side as far as possible. A broken mount will be clearly visible, and a partial crack will squirt bilge juice. You might look at a similar engine that doesn't vibrate [as much] first.