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older 9.9 powerhead replacement options late 70's

J

joeboo

New member
Hello,

I have an older merc 9.9 (late 70's) with compression problems. I was told by mechanic that there is cylinder wall scoring. I would like to attempt to fix this myself. Any idea where in Ontario I could get rebuilt or used powerhead?

Thanks,

J
 
Re: older 9.9 powerhead replacement options

First have to figure out exactly what you have. 9.9's only started production in 1986. There was earlier 9.8's (formerly the model 110) built between 1965-85. They are quite different motors and depending on exactly what you have that will determine possible other donor models. There was also a number 9.9 Mariners that were built by Yamaha and are a Yami model, nothing like the Merc's.

These Mercs were "headless" motors and there was no allowance for them to be rebuilt (they can be honed but you can't bore them and put in an oversized piston), so a powerhead swap is the only viable option if the cylinder damage is significant enough - a light score could possibly be honed enough to make it work, but anything signifcant means the powerhead is dead.

So depending on exactly what you have, I can maybe point you in the right direction. If you have a serial number, post it up - alternately, from a picture, I can figure out what you have and what will work with it. And I'm in Ontario, so also may be able to point you to a shop in your area - I either know of or have heard of numerous quality places around the province....
 
Re: older 9.9 powerhead replacement options

Well, I am assuming it is 9.9 as that is what the cowling says. Also, from the serial number -- 0B191778 -- I now think it is a 1987 outboard!
 
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Re: older 9.9 powerhead replacement options

Not today, motor is at cottage and I am still using it, it is just slow!!!
 
Re: older 9.9 powerhead replacement options

I have only had the motor for about a month. I got taken by someone selling it used and have learned the hard way to perform compression check first. I took it to mechanic after I ran it on lake and found it rough and underpowered. It was the mechanic that told me the cylinders are $crewed and not worth repairing.
 
Re: older 9.9 powerhead replacement options

Yes, I have learned my lesson. I like the motor (electric start) and it charges my trolling motor so I am hoping to salvage it.
 
Re: older 9.9 powerhead replacement options

Sorry, been quite busy the past week or so.

Your "serial" number, which is really just a production number, does not have any usable information (such as horsepower, year built, plant code etc) encoded into it - it's just a "next off the line" number.

But you are correct - it is in fact a 1987 model.

The 87's shared a powerhead with the 6 and 8 horse motors (all 6, 8 and 9.9's built between 1986 and early 1994 used the exact same powerhead). The 9.9 had a different carb and the exhaust plate/tube was different, but that is easily transferred over to another powerhead.

Unfortunately, these motors were extremely well built and they don't show up very often at recyclers unless the powerhead is shot.

There is a place in Peterborough (Marine Medics) that reman's powerheads, but you will find it "not worth it" on small motors like this. A reman 9.9 powerhead sells for almost $1200 - and they rarely have small Merc powerheads - AND, you can pick up a used 9.9 complete (late 90's vintage) for 300-400 bucks less than that in the used market. So in this particular case, a reman powerhead is probably out of the question.

That leaves you with Ebay or Craigslist (or any of the sites like those) - maybe you can pick-up a 6, 8 or 9.9 that has a toasted lower unit (still pretty rare) - however, in the end you may simply have to find another used motor and use your current one for spare parts - or part it out and sell off the pieces - a good lower unit will bring in a couple hundred bucks, you could pick up another hundred of so for the ignition etc - most motors are worth more if you strip down the parts then they are a whole unit...
 
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