Help! Powerhead Swap?

[bojango541]

I have a 1989 45 HP 4 cylinder Merc. that sank a little while back, and has some other issues as well, so I was looking for a new motor. Picked up a 1980s 40 HP merc, 2 cylinder motor. Everything looks pretty similar except for the fact that it is a 2 vs 4 clyinder. My original motor has power trim, and the new one I purchased does not. I would like to put the 2 cylinder powerhead on the motor with the 4 cylinder powerhead and power trim. Will it bolt up? Will I have any problems doing this?

Older 2 cylinder 40 HP:


45 HP 4 Cylinder:

 

[Maxz695]

Re: Help! Powerhead Swap?

Check the long studs and see if there the same for powerhead bolt down. The midsection on the 40 is the same through 70 except the adatper plate which is about 1/2 inch longer. (per my adaptation from 1979 40 Hp to 1979 70 HP. also make sure the exhaust base plate is the same as yours and I see no reason why it can,t be done other than the electircal harness which may not be a factor oil injection allarm etc. These wires won,t be nesecary on a 2 stroke and can be tapped off. I have threaded stainless steel rod left over if thats your only issue. I can send for the price of shipping if you decide to undertake it and thats your only issue. The lower units should be compatible as long as it,s not a bigfoot Then I,m at a loss. No need to mess with the trim tilt as far as I can tell.as long as the midsection joining surfaces match. and the splines have the same number of raise on it.