Power head swap?

[freeisforme]

Will the power head from a 1977 Evinrude 140 fit a 1976 Evinrude 135 hp lower and mid?
I've got a minty 1977 140 power head with a bad lower unit and a 135 with a bad power head.

 

[emdsapmgr]

Re: Power head swap?

No. OMC changed their thermostat housing and subsequently powerhead mounting in 1977. They are not compatible.

 

[freeisforme]

Re: Power head swap?

Will the 1977 140743S power head fit any other year?
I hate to just junk or sell off a good running motor just because the lower unit is trash.
I'm trying to find a way to put some odd parts together to get back out on the water this year. I've got a 1976 mid and lower from a 1976 that blew a rod out the side, another 135 with no compression, (Badly stuck rings from sitting for 30 years). I looked at a blown up 1986 on CL that needs a power head but things looked pretty different between the two?

In my search for a lower unit, I found that 1977 was a one year deal, and nearly impossible to find and this is a 25" shaft motor as well.

 

[emdsapmgr]

Re: Power head swap?

Your powerhead will bolt to midsections up through at least 1994. What changed was the shift rod mechanism under the bottom carb.

 

[freeisforme]

Re: Power head swap?

Where there any other motors that would use that same lower unit? I've looked high and low and found nothing in a 25" shaft/hydro mechanical lower unit to fit the 140743S motor. The lower I have is totaled, it needs a driveshaft, all bearings, and seals. It sat for a long time a seized up. The worst part is that the motor has very few hours since new. It's just sat forever. The t/t, power head a mid section are mint.

 

[Lion hunter]

Re: Power head swap?

Not sure about putting the power head on the 135 lower, but according to this chart your 135 lower will fit the 140 (just opposite of what you said I think). Not sure about the mid section.

http://forums.iboats.com/showthread.php?t=359907

 

[emdsapmgr]

Re: Power head swap?

The 73-76 lowers were non-electric.

 

[Dhadley]

Re: Power head swap?

The 77 140 can be made to bolt up. There are two mounting bolt holes on each side that have to be changed. There are places that have the jigs to do that quite easily. If you compare a 73-76 mounting gasket to one for a 1977 140 (not 77 115) you'll see the difference. The 77 140 was the first motor to pick up the later bolt pattern. Every V4 crossflow from 78 & newer use the later pattern. Been done thousands of times.

The 73 powerhead cannot be made to work on the 77 mid section. You'll always end up with a water leak under the powerhead at the adaptor plate area.

 

[freeisforme]

Re: Power head swap?

So there's a chance that the '77 140 power head will fit onto the 135hp with changing or modifying a few mounts?
Anyone got any pics of the changes that need to be made?
If I can combine these two, I'd have a minty perfect motor to get me back in the water. Just with a different style tilt and trim now.

It looks to me like the '77 140 was all new except for the lower unit?

Too bad the newer lower unit can't be put on to the 1977 140, I've got a few of those around.