Bolts for an outboard????

[Jon Fuller]

Originally Posted by TheOrs

The 'land' on the bolt is important as it provides location & alignment but (if I remember correctly) it's less important here because the holes in the outboard are significantly bigger than the bolts. Bolts are locating & fastening devices (threaded only part way), screws are for fastening only (threaded all the way) but that's a whole other thread & there are lots of people who are going to have a different opinion on this.

Yes, the bolts, holes in the saddle, and holes in the transom, are way too sloppy to be considered the 'locators'.
What stops the motor shifting laterally (upon which, the road to getting very lose and ultimately, falling off, is very short), is its friction/stiction with the transom, achieved by massive clamping force exherted by the hairy chested, fine thread, 1/2 bolts.
Again, I would say that metal to metal mounting is far worse for this as the fitment is unforgiving from a friction standpoint, and the natural compression of the timber in a transom helps keep things tight. And the practice of fitting a pretty, but rather slippery transom plate isn't really the best option.
Bedding the motor saddle into a ply pad, or even directly onto the glass transom (as Steve Baker reccomends) is the favoured method, though I'm sure in the current climate of 'Bling is beautiful', it wouldn't be a popular one.

[TheOrs]

Originally Posted by Jon Fuller

...And the practice of fitting a pretty, but rather slippery transom plate isn't really the best option.
Bedding the motor saddle into a ply pad, or even directly onto the glass transom (as Steve Baker reccomends) is the favoured method...

I noticed recently that over the (13!) years my motor has dug itself slightly into the 'glass of the transom. (It's not loose 'cause it's been off/on several times & hence re-tightened).

I was thinking of getting one of those fancy transom plates made up to stop this but you have just changed my mind, put it at rest, saved me some money & a little bit of hassle.

Cheers!

[Thunderbird Racing]

Have to admit i had fitted a new stainless transom plate the start of that season because the old ally plate had distorted and the engine had sunk into it so perhaps ally plates are better as the shape into the transom and stainless far too hard.