Outboard motor mounting

[CJ]

Before I drill holes in the transom of my skiff for the through-bolt mounting bolts of my outboard, I wondered if these holes are standardized on all outboards. Not the clamping mechanism, the holes for through bolting. Does anyone know if the distance between these holes is standard for motors from, say, 8 to 40 hp for all manufacturers? And, if so, what that dimension is?

[RodB]

This is a standard pattern and you can get the boat shop jig from any local dealer (try to rent it for a couple of hours or use it at their shop).

This jig hangs atop your transom and has brass bushings lining the holes. Just hang in on and clamp it with two C-clamps at the top edge of the transom. When you drill the holes ( 1/2" standard), if you get off square you hear a loud squealing noise. Avoiding this noise allows you to drill relatively square holes.

If this is a wooden boat be sure to enlarge the holes enough to account for a few coats of epoxy before installation of the bolts with silicone or 3M 4200 sealant.

Note: don't use silicone anywhere where you ever may want to paint. I suggest "Goop" or 3M 4200... clear adhesives like "Goop" are definitely easier to remove if you ever have to change motors, etc...

RB

[ 07-13-2004, 12:58 PM: Message edited by: RodB ]