Tohatsu MD90A Vibration at low revs

Hi,

I have a Tohatsu TLDI MD90A From around 2001 which vibrates/resonates at slow speed (just once you have it engaged in gear and a hair higher RPM - between 800-1000rpm I would say). If I push further it disappears but it is right at the spot where I need to move around the harbour so is not really pleasant. I think I was told a while ago that this is a trait of these earlier models which cannot be rectified and something to do with a rubber part in the gearbox, but I cannot remember exactly.

Was just wondering if anyone can confirm whether this really is unfixable or whether there is something I can do to make it run smoother at these low RPMs?

Thanks in advance.

I found some old communication I had had with Tohatsu a few years ago. Apparently this is due to the engine running lean at idle and setting up a vibration in the drive shaft that is made a lot worse by plastic hubbed propellers. A change to a rubber hubbed propeller should help a lot apparently. Since I have to change the pitch of my propeller anyway, I will try this. My current propeller is a mercury with what appears to be a hard plastic hub.

Correct on all counts.