rebuild or sell parts? 1982 70 hp serial # 6163944

JKTrevecca · Mar 22, 2014

I picked up a 1982 70 hp today that the prior owner was running at WOT yesterday when he heard a "rattle" and now the engine is locked up. I haven't torn into it yet to see how bad it is. I paid $45 dollars for it and got the entire assembly with the detached/external trim pump and hoses, all of which work. The motor is clean and as far as I know, the lower unit is good, the electronics are all good, and it was running great until the catastrophic internal failure.

Assuming it broke a rod or has a hole in a piston, I'm am weighing the option of re-building it or selling the parts. Is there a market for used parts? If so, would e-bay be my best option in your opinion?

How much would the trim pump be worth used? Lower unit? etc...

Lastly, would I be able to use the trim assy on my non-power trim 1979 2cyl 40hp Merc? What all would I need to do to make that work if it's even possible. Could I somehow swap my 40hp motor onto the transom bracket this motor uses?

Thank You!

Mi duckdown · Mar 22, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

45 bucks nice steal. Do your home work on ebay

1FASTLASER · Mar 23, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

If u are mechanically inclined and actually have a place to put the motor on tear it apart and then make ur descision. In order to sell the parts you have to tear it apart anyways. Then go from there

gm280 · Mar 23, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

I'd lean towards repairing it, but I love refurbishing things. :facepalm:

As stated above, tear into it and see exactly what it would take to make it run properly again. If that seems too expensive, part it out. But selling USED parts is not as a quick issue as some think. There has to be folks needing your exact used parts and willing to buy them. Most would like new parts. But it is your decision.

jbjennings · Mar 23, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

I would sell the parts. I would be very leery of using ebay, because their fees are high and because of the hassle and headache of dealing with the public. craigslist can be handy, but has its own dangers with wackos showing up to your house---maybe meet at a location away from home.
I would sell the parts because it's pretty darned expensive to rebuild a powerhead if you have to replace pistons, have boring work done, and get new rods and such. It may not even be rebuildable.
I like the comment above about tearing it down since you have to in order to sell the parts. As said, you will know how bad the damage is then. It could easily be fixed for just a few dollars, although unlikely if it cratered during full throttle and seized.
JMO,
JBJ

JKTrevecca · Mar 23, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

Thank you all for the replies. I disassembled it today and found the bottom rod was broken. I'll post detailed pic tonight after the kids are in bed. So... couple more ?'s in the meantime. Is there a way I could use the transom clamp and trim unit on my 1979 mercury 40hp? And... is the lower unit the same as my 79? Thank you a ton!

JKTrevecca · Mar 23, 2014

Re: rebuild or sell parts? 1982 70 hp serial # 6163944

So the connecting rod on Cylinder # 3 (bottom cyl) was broken and did some damage to the crankcase and very bottom of the cyl itself. I've attached several photos. Any opinions on whether this would be worth rebuilding. looks like I would need 1 piston (unless i could clean and measure # 3 and be convinced it's ok to re-use, 1 connecting rod, machine shop to work on the crank journal, + a gasket kit at the absolute minimum. If I want to rebuild it "right", i would need a lot more than that. I'm not at all worried about being able to complete the repair/rebuild. It's 100% based on whether it would make financial sense. I've rebuilt 3 automobile engines and several small/lawnmower engines. Any advice or thoughts about cost effectiveness or "what would you do" are requested here.

Lastly - Could I use the trim unit and pump (or lower unit for that matter) on my 40hp merc shown in the last photo? it's a 1979 model. I might keep the lower unit just as a spare/for parts.

Thank You!