my new ship humber destroyer

[ChrisParish]

Looking good!
I noticed that the holes for the engine bolts were drilled in one of the above pictures where the boat is on the trailer. Did these come pre-drilled? If so is there a standard spacing for outboard bolts?

[beerbelly]

thanks for rotating the pics Chris I couldn't find anyway of doing it .
yes the transom is drilled i asked Ian if he would drill it for me as i wasn't confident of getting the holes square and he has a jig to do it and as far as I am aware all later outboards use a standard bolt pattern but I told him it was for a mercury f100 just to be sure . As it turns out mounting the outboard gave me my first snag .It turns out my outboard is a 25 inch leg xl shaft and the ribs transom is 21.5 inch for a long shaft outboard so to get the vent plate level with the keel I had to mount the outboard on its lowest mounting holes not ideal and I'm not sure if I'm going to leave it like that or look into getting a jack plate . my mate recons though if it wasn't ok to use those holes mercury wouldn't have fitted them lol . I found this on ebay would do the trick
https://www.ebay.co.uk/itm/CMC-Static-J ... SwK-1dH3el

[ChrisParish]

I had noticed it was mounted very high, but I didn’t know if you had mounted it in it’s finished position.

The thing with the pictures is a quirk of mobile phone cameras and the forum. The phone always takes the picture in the same orientation and includes some info hidden in the file about how to show it. The forum can’t read this so sometimes it gets it wrong.
The easiest way to make sure they are correct is to crop the images on your phone before uploading - that way they come out the correct way up!

[sonny1]

possibly a stupid question but the jackplate at £215 isnt cheap, could you not demount the engine and redrill the holes in the right place?. or could it be the transom isnt deep enough

[sonny1]

That sure is a lot of money for some aluminium angle. You need to find a friendly fabricator who could make you that for a fraction of the price.

Terry, I think the real issue is that the leg is too long for the transom - re-drilling the holes nearer the top would not really be a fix.

My only concern with having the engine up so high is that relatively little of the clamping surface is in contact with the transom, so the load per unit area is going to be higher. It might not be an issue - I am not an expert and I tend to over engineer things.

[beerbelly]

that is my concern Chris I have been told it will be fine the outboard saddle where it sits against the transom is flat top to bottom and if there was any flex in the transom then it not contacting above the holes might make a difference that's why I'm contemplating the jack up plates and if it does a job I don't mind paying a couple of hundred . mind the saddle is a very substantial casting .
and sonny1 the holes are already drilled as high as they can be as recommended by humber so that's a non starter even so would need to make up 5 inches

[sonny1]

could the xl shaft be reduced to to just long also if you are picking the motor up 5 inches then with the engine fully tilted up it will encroach into the boat the same amount .is that likely to have any knock on effect?

[ChrisParish]

Raising the engine will actually reduce the amount by which the engine encroaches into the boat because the transom is angled back and the pivot point has also been raised. It would only encroach more if the pivot point remains in the same place relative to the transom and the engine moved up.

[sonny1]

yes well explained chris but what about shortening the shaft

[Roy54]

Or a brand new longshaft engine!!! just saying