Older 85hp will not engage when under load.

jhow0228 · Jul 11, 2013

I am posting this for a friend of mine. He found a log in the water and since has been a nightmare for him. He first thought it may have been the hub, so he replaced it and no go. He took the boat to a local boat mechanic and was told he needed to replace the control box. They did and it still will not engage. They have also replaced the whole lower unit with no luck. The kicker: boat will engage while hooked up to the "muffs" but will not when the foot is submerged. 85hp evinrude. Thanks in advance for any help.

fireman57 · Jul 11, 2013

Re: Older 85hp will not engage when under load.

Try unhooking the cable from the shifter and get on the water at the dock or on the trailer and see if he can shift it manually in the engine compartment.

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

fireman57 said:
Try unhooking the cable from the shifter and get on the water at the dock or on the trailer and see if he can shift it manually in the engine compartment.

He has already done that. That is why they replaced the control box and cables.

fireman57 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Did it engage manually?

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Motor will engage manually or with shifter when out of the water, but will not either way once foot is submerged.

fireman57 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

I have to tell you that I have no clue what it could be. Gremlins? This one has me stumped. I'll keep pondering it though. If somebody figures it out make sure you post the solution here.

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Will do. One more piece of the puzzle is that it will go into reverse. We do know it isn't control box, cables, or the lower unit. Could it be the drive shaft? Or where it goes into the powerhead?

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Talked to a guy and he said it could be a double clutch in the motor that has gotten twisted. Sound like a possibility?

dazk14 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Year and model? Just model# will work and we can tell you the year.

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Model 85793. Yr 1977. 85hp evinrude

fireman57 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

There is no such thing as a double clutch, there is a clutch dog. If could misaligned but I can't see that happening in two different lower units. Did the other lower unit go in reverse?

jhow0228 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

Yes.

crestlinermusky · Jul 12, 2013

Re: Older 85hp will not engage when under load.

jhow0228 said:
Yes.

I have a 1975 Evinrude 115 and I have seen a problem like this before.
At the top of the shift rod where it comes out of the exhaust housing under the
carburators. On the top of the shift rod is a fitting that connects to the pin on the shift linkage.
Inside the hole of the fitting is a plastic spacer that takes up the slack so the pin on the linkage fits tight.
Without that spacer the foot will not engage in her gears properly, causing the foot to disengage into neutral.
Reverse will engage because the rod pushes downward
Let us know if this is it

fireman57 · Jul 12, 2013

Re: Older 85hp will not engage when under load.

crestliner you might be on to something there.

jhow0228 · Jul 18, 2013

Re: Older 85hp will not engage when under load.

I finally got to look at his motor myself. That piece you are talking about is there. I'm pretty sure it is the clutch dog. He has a certified mechanic coming out in a week to tear the lower unit apart. Will let yall know the outcome of it.

Fed · Jul 18, 2013

Re: Older 85hp will not engage when under load.

I'm pretty sure it is the clutch dog.

But he has already changed the lower unit?
Two lower units with the exact same problem would be unlikely.

Stripped crankshaft spline but you'd think they would have noticed bits of metal when they removed the lower unit?

I like a mystery.

fireman57 · Jul 18, 2013

Re: Older 85hp will not engage when under load.

I'm with you Fed unless they just told him they replaced the lower unit. Can't imagine two lower units with bad clutch dogs. Been having some cold brews and hard boiled eggs tonight. I think somebody opened their lunch.

jhow0228 · Jul 19, 2013

Re: Older 85hp will not engage when under load.

I know. I'm completely stumped. The other lower unit they put on it was old as well. He currently has his lower unit off the motor. If you pull/push on the shift rod, shouldn't it move? His was locked up and in gear.

fireman57 · Jul 19, 2013

Re: Older 85hp will not engage when under load.

you should be able to push/pull and change gears with it off. Time to tear it down and see what is going on.

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