Posted by Project13 on 07/04/11 - 6:23 AM
#1
I have a 1967 hull and a 1980 50 hp Evinrude short shaft to put on it. I need suggestions on is how to mount the motor since the holes do not line up. My guess would be I or someone will need to drill new holes to mount it. I don't want to do this and so I might take it to a mechanic to do it, but wanted to see if anyone had any ideas of another way. The holes miss by about 1-2".
Thanks.
Edited by Tom W Clark on 07/04/11 - 9:32 AM
Posted by Tom W Clark on 07/04/11 - 8:50 AM
#4
Yes, you need to drill new holes but first you need to fill the old ones. Drilling new holes is very easy.
In 1980 Evinrude did not make a 50 HP outboard, they made a 55. Are you sure you have a 1980 model?
This question is not trivial as the mounting bolt layout changed for the OMC two cylinder 50/55 models over the years.
Posted by Project13 on 07/04/11 - 1:09 PM
#5
E50ECSR This is the model number on the motor. Boats.net list it as an 80.
Posted by Tom W Clark on 07/04/11 - 7:52 PM
#7
You are right, I just looked up the original catalog. In 1980 they split the 55 into a 50 HP model and a new 60 HP model.
The 1980 models used a mounting bracket with BIA Standard bolt hole spacing, which most motors used on 13 footers do not use.
The best way to fill the old holes is to drill them out so they are clean then glue in plugs of wood and 'glass and gel coat over those plugs.
Note that I said PLUGs not DOWELs. Do NOT use dowels, you want to maintain the grain orientation of the wood.
Just cut some plugs from a soft wood like Fir or Pine. You want to match the wood in the transom as best you can and the original wood in there is Fir plywood. Do not use Mahogany or Teak, they are too hard and dense and there is no need for the added expense.
The easiest thing to glue them in with is Polyurethane glue (Gorilla is one brand) and then trim the excess after it has cured. For a clean finish, I use a Forstner bit to cut an oversized but very shallow hole which is then filled with resin and top coated with color matched gel coat.
In reality, you can also just fill the old bolt holes with a polyurethane caulk like 3M 5200, but you asked for the BEST method...