1979 merc 80hp power trim questions

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Apr 4, 2011
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29
I just replaced the junk 85hp Force on my 89 spectrum with a 79 mercury 80hp. I had power trim on the old motor, and the new one does not, and after a few times out on the erie canal I really miss having power trim/tilt. I found a power trim set-up for a newer 90hp mercury and I know it looks different, but if the bolt pattern is the same, I can make it work I think. Has anyone done this, or am I better off trying to find the correct one, or buying an aftermarket one? Other than not having power trim, this motor is awesome, and even though its rated less hp, and is 10 years older, it runs way better than the Force ever thought of running!
 
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Apr 4, 2011
Messages
29
Re: 1979 merc 80hp power trim questions

Does anyone know what the center to center distance is on the bolts that mount the newer style trim unit to the motor? Some guy has one off a late 80's 90hp merc, and would like to know if it can bolt up before I make the 2 hour ride out there
 

Chris1956

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Mar 25, 2004
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27,036
Re: 1979 merc 80hp power trim questions

If the new PTT unit is the two cylinder, 4 pressure hoses plus power trim motor and reservoir that mounts in the boat, it will fit your motor. Be sure to get the PTT brackets as the cylinders do not attach to the same places as the shocks that you now have. If it is the newer style 3 cylinder and motor mounted on the transom bracket, you would need to install the whole triple clamp and transom bracket assembly. I think the changeover to the new style PTT system took place in 1984 or thereabouts...
 
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Apr 4, 2011
Messages
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Re: 1979 merc 80hp power trim questions

Thanks for the reply! the PTT that Im looking at is the newer 3cyl style with pump on the transom bracket. Looks like this guy has everything from the outboard pivot point/trunnion(not sure the outboard term for it, im a farm equipment guy) to the transom bracket. Also, the guy says the pump is bad, but is unsure if its the pump itself, or the motor. Either way, a pump, or electric motor rebuilt does not bother me, but I also don't want to spend a ton of money on a new pump/motor if it is not rebuild-able.
 

Chris1956

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Joined
Mar 25, 2004
Messages
27,036
Re: 1979 merc 80hp power trim questions

I have never made that changeover. I therefore cannot predict if it will work. There are some on the forum who have made it. Maybe they will chime in.
 
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