Changing 93 Evinrude to 90hp to 77 Evinrude 85 hp

[kmcburnett]

My 93 Evinrude 90hp went sour on me. I have picked up a 77 Evinrude 85hp and want to know the differences / problems I will encounter changing these two out. I already see the tilt systems are different which stinks cause the 77 tilt does not work. I also see that a shifter cable is different (both on the 93 bolt on while the 77 one bolts and one clips) and it looks like the 93 has an extra wiring harness compared to the 77.
Are these two units interchangeable? or should I just try and find another 93 motor?

 

[emdsapmgr]

Re: Changing 93 Evinrude to 90hp to 77 Evinrude 85 hp

The undersides of the powerheads changed between those two years. As long as you keep the powerhead matched to the original midsections, you are ok. The red plugs on the main control box harness are identical and will plug. The ends of the control cables are different. You'll have to adapt them on the engine end, or get a 93 control box. Somehow you should be able to get these cables to work. The power trim also changed around 1981 or so. Went from the older 3-wire system to the newer 2-wire system. While the older system used the separarte trim control box, you can swap the newer trim system to the old engine. The only problem will be that the older engine does not have mounting holes on the back of the exhaust cover to mount the newer trim box. You can swap the outer exhaust covers. One other thing, the old 77 was hp rated at the crank. The newer one was hp rated at the prop. The newer engine will have about 12-13% more hp than the 77, plus the 5 hp difference to start with. That could mean a 13 hp difference.

 

[Faztbullet]

Re: Changing 93 Evinrude to 90hp to 77 Evinrude 85 hp

Somehow you should be able to get these cables to work.

Just pop the clip off and install it on new cable....

and it looks like the 93 has an extra wiring harness compared to the 77.

Thats for the VRO and oil tank in boat...

While the older system used the separarte trim control box, you can swap the newer trim system to the old engine.

Sorry but midsections are different and you cannot install a 3 ram system into it....

 

[kmcburnett]

Re: Changing 93 Evinrude to 90hp to 77 Evinrude 85 hp

Thanks everyone for the help. I got it changed out and all is well. The motor went right on and the wiring harness plugged in. I took off the older tilt for now and will try and replace the seal in one of the cylinders. All in all it went perfect.