Bolt or clamp?

ontherocks

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Would you recommend clamping a 25 hp tiller mercury engine to the transom, or should you thru-bolt it. One dealer said that I could just
clamp it, the other said I should bolt it. If I could get away with just clamping it, I would love to. Not sure which way to go.
 

stircrazy

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It really depends on the application. That being said, if its going on a commercial boat or is going so see relatively heavy use i would definatley go for bolting it on. A halfhour spent lining it up and drilling the holes and a few bucks spent on a good sealant (3M 4200 or 5200) to seal the holes will save you a lot of headaches down the road. A bigger out board like a 25 hp will put some force on a transom and flex it a little. Over time with just the clamps gelcoat will start to crack and allow water intrusion to important transom laminates.

Though, if your confident you've got a strong transom and are only using the boat lightly for recreation, you may be able to get away with just clamping it. You must be willing to tighten and check the clamps on a regular basis though.

Weight is also a big factor. if it 4 cycle heavier outboard I would bolt.
 

scallywag

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I would definitly bolt it on. The bottom of our river in the Chesapeake is littered with outboard motors that people underestimated the twisting torque put on the transom. I have a Yamaha 20hp 4stroke on my 16'skiff.
I agonized about drilling holes in my transom, but in the end it was only two small 5/16" holes. The peace of mind is worth it and it makes it alittle harder for someone to steal your outboard.
 

ontherocks

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Thanks for the funny reply and the good suggestions.
It looks like i'm going to drill. What type sealant would
be recommended for the holes?
 

scallywag

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I would agree with STIRCRAZY 3M 4200 or 5200. It won't take much to seal the bolt holes.
 

jojobee

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I would drill, seal with epoxy then use boat life on the bolts
 

ontherocks

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Have you heard of "Life Caulk" as a sealant. The marina that i ordered
the engine from recommended it.
 
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