40hp Johnson powerhead swap 1990vs2000

[Seacraft]

I have a 1990 40 hp with a bad powerhead. I purchased a 2000 40hp complete short block thinking it would be a easy swap of parts and I would be back on the water... Problem is the front case half of the power has different holes drilled in the casing where the shift parts connect. Can I swap out the case half of the new motor with the old one that has the correct casing holes. I know on other larger engines these are matched pieces but these little 40hp dont have sealing rings between the case half. Anyone have any suggestions?

Thanks in advance

 

[racerone]

Re: 40hp Johnson powerhead swap 1990vs2000

The commercial models may have had different shift rods, thus the different location of these holes.-----Have you checked whether the spline on the bottom of the crankshaft is the same ?

 

[Seacraft]

Re: 40hp Johnson powerhead swap 1990vs2000

Yes the splines are the same.

 

[Bosunsmate]

Re: 40hp Johnson powerhead swap 1990vs2000

id tap some new holes

 

[Seacraft]

Re: 40hp Johnson powerhead swap 1990vs2000

id tap some new holes

problem is the area over laps another area where hole is already drilled. Would have to weld up 1/2 inch hole were current shift lever hole is and drill new again. Would really be a pain. Its only off by 1/2 or so but enought it's not going to work the way it is.

 

[Bosunsmate]

Re: 40hp Johnson powerhead swap 1990vs2000

problem is the area over laps another area where hole is already drilled. Would have to weld up 1/2 inch hole were current shift lever hole is and drill new again. Would really be a pain. Its only off by 1/2 or so but enought it's not going to work the way it is.

Fill hole with epoxy and then re drill the hole where you want it.

 

[Seacraft]

Re: 40hp Johnson powerhead swap 1990vs2000

Fill hole with epoxy and then re drill the hole where you want it.

Thanks but epoxy isnt going to work in this location and be lasting anyway. Just a bad spot for that type of repair.

 

[racerone]

Yes you can but you need to check shimming of the pinion gear.