motor mount bolt torque

[jupiter12]

i have an old hourston 17'. the motor mount bolts are tightened enough that the washers noticeably compress the fiberglass liner against the transom, I wouldn't say to the point that it's cutting through the fiberglass but to the point that the bolts are denting the fiberglass. Is this normal or should I be undoing the bolts and putting a metal plate between the bolts and the transom (which I do have available) The transom seems very strong, no cracks or flex except around the engine when I push and pull on it and only a tiny bit. The engine is a 1995 Mercury 60 hp. Approx. weight is 220lbs. thanks, sean

 

[Bob_VT]

Re: motor mount bolt torque

Welcome to iboats.

Yes it sounds like there is a significant stress there. If you can fit a plate (Stainless steel or aluminum) there to protect the transom on the inside I would. If you crack into the fiberglass you are creating a pathway for water and eventual rot in the transom.

When/if you do this make sure you coat the bolts before you insert them with 3m4200, put a layer between the plate and the transom too.

 

[jupiter12]

Re: motor mount bolt torque

thanks for the reply, one more question... after i have put the new plate on the motor, how tight do i make the bolts or is it just until there tight?