can u patch omc transom hole to suit smaller sternleg

the 5.6m boat ive purchased has a rubber bellow that seals the omc sterndrive to the transom, im looking to upgrade engine sterndrive package but the gapping hole in transom after the bellow comes out will be to big for later model sterndrives.Can the hole be patched and recut to suit keyhole style sternlegs or other, or do i have to replace transom. Big thanks to any help

 

Yes.... but can't give precise advice how before knowing the structure of the transom..

 

transom hole

the transom is a single peace of ply about 400mm thick very solid 2m width 1m hieght, it looks like 90 % angle. the main stringers are 600mm apart and run half way up the transom,high floor, the hole is a rounded square 400mm by 400mm and sits 100mm away from each stringer, 120mm from the bottom. its not a case where the ply wood slides out from between fibreglass,its simply a single peace of ply attached to the back and glassed on both sides,the stringers but strait up to it, had a boatbuilder check it before purchace he mentioned it may have bin converted to inboard but the transom has been done well and is solid.

 

Making a big hole smaller is always a challenge. You can make a plug the size of your current transom opening from a wood epoxy laminate, cut the pattern for the new outdrive in the plug, then secure it in place using epoxy and cloth. Best of luck, it's a tough job for pro's.

 

holy boat

Thought so considering pressure load on the transom, if i tried to fix it without expert help,id be $#!+ing my self out at sea not to mention the responsability of the saftey of mi mates in my bodged up boat. took the floor out and stringers need replacing,once there out is it possible plug the entire transom on the inside of the boat with ply cut to shape and run the new stringers up to it and then fill in the hole on the outside. would the transom be to thick for around 150 hp 2000 model onward sternlegs. Not to sure about out o/b trani pods.Strength is my concern, would a ply plug be strong enough if installed properley.Ive been reading about people doing i/b to o/b conversions in witch the sternleg hole is plugged, then an alloy plate attached.Am I in the same boat as them,without the alloy plate.

 

Question though, why do you want to change the drivetrain. While OMC is out of business parts are plentiful and fairly inexpensive if you know where to look. I have a 38 year old OMC electric shift that still gives me great service with just regular maintenence.

 

scratching my head

Good point. The engine is an old nissan diesel with a 1970s 235hp rated omc leg. the engine and omc wieghs a tone and both need parts. I got a price on a 2003 150 hp turbo diesel mercruiser with leg $4000 a lot lighter all ready to go. The engine uses a steel framed engine mount so that might have to be taken out and new mounts built for new engine. Would it be cheaper and lighter to go o/b transom pod conversion if i get an o/b for the same price as i/b more deck space would be good.

 

Ok, I understand now. It might be a bit easier to convert to an outboard but you are still facing a bunch of work but an outboard for that size boat might be the most efficient means of operation rather than all the weight of an i/o drivetrain.

 

I can see the light

o/b conversions the way il go ive been reading threads on them,seem to work well when done right. thanks for the help aprieciate it.

 

Two square metal plates, some plywood and stainless bolts, plus a bit of Sikaflex is what you need for the conversion. You could use anodized aluminum or stainless but it I would use aluminum because it is easier to saw a hole for your Mercruiser drive.

The only other option is plywood, resin and at least 8 layers of glass on each side of the transom, which altogether may look nicer if you've done it right, but it's a lot more work.

 

Can anyone reccommend an OMC electric shift stringer mechanic in the long Island area?