Will this 1975 50hp Powerhead fit my 86 50hp?

timmeraw

Petty Officer 1st Class
Joined
Jun 10, 2008
Messages
258
I had what I believe is a 1986 50 hp (sn A931335) with power trim/tilt that blew a cylander. Everything but powerhead is still on my boat including leg and foot and controls.

I have a chance to pick up a good running 1975 50hp Merc 500 and I am wondering if I can just remove the powerhead off this motor and bolt it onto my 86 leg/lower etc?

Thanks.
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: Will this 1975 50hp Powerhead fit my 86 50hp?

I would have thought that the powerhead gaskets would be the same, but I looked it up and there are different gasket numbers for the powerhead-to-tuner gaskets.

However, the lower gasket (exhaust tuner plate-to-midsection) numbers are the same between both motors. So if you were to take the entire upper end assy from the older 500 including lower cowling (and likely the tuner as well), the whole mess should bolt up to your midsection.

The only issue I can think of other than that would be if there are any differences between the older and newer transom-mount assy's that would cause the older lower cowling to interfere with, say, the steering arm or something like that.

If you do the swap, be sure to use the later-model's upper shift shaft assy, as if I recall correctly the shift shafts on later motors may be square, whereas the earlier ones use splines. Obviously it'll have to match whatever's still bolted to the boat!

Anyway, sounds like it might be worth a shot, worse case it's just a few hours of wrenching and a couple of gaskets.

HTH & let us know how it turns out.........ed
 

timmeraw

Petty Officer 1st Class
Joined
Jun 10, 2008
Messages
258
Re: Will this 1975 50hp Powerhead fit my 86 50hp?

That's great new's Ed. Thanks for taking the time to answer. Have a nice day.
 
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