Need to Bolt Motor to Transom?

[Ducats]

Hello,
I just purchased a 14' Mirrocraft aluminum boat w/o a motor. I'm now looking at getting a 1977 20hp Mercury motor for it (boat is rated for a 35hp motor). My only other experience with motors was a 9.9hp motor where I just tightened the clamp screws to the transom. Given that it's bigger, will a 20hp motor need to be bolted to the transom?

If so, what do I need to make sure I do in order to ensure that everything is done correctly and I don't have any problems with the transom or motor? Thanks in advance for your help.

 

[tashasdaddy]

Re: Need to Bolt Motor to Transom?

the 20 will have transom clamps, but should also have lower bolt holes. these help in the theif problem. stainless steel nuts, bolts and large washers, some dow 4200 to seal the bolt holes.

 

[Chris1956]

Re: Need to Bolt Motor to Transom?

Ducats, Bolt the motor if you can. I lost a 50HP Johnson as well as my old 5HP motor off the back of the boat, since neither were bolted.

BTW - I got them both back. The 50HP didn't seem to mind beiong dunked into salt water while running at high speed, the 5HP never ran well again.

 

[tashasdaddy]

Re: Need to Bolt Motor to Transom?

the bolts won't stop the thief, they just give you time to get the shotgun.

 

[Joey One]

Re: Need to Bolt Motor to Transom?

I almost lost everything when the clamps loosened off a lee shore. Since then, I always use thru bolts. I install stainless carriage bolts from the outside and use
double lock nuts on the inside. It's very difficult to remove them.

 

[Ducats]

Re: Need to Bolt Motor to Transom?

Thanks for the responses. I checked the motor again and did see the lower bolt holes. Looks like my next step is to go buy the stainless steel hardware and start drilling the holes in the transom.

 

[WillyBWright]

Re: Need to Bolt Motor to Transom?

Ultra Silicone makes a good readily available sealant.