850 Merc.

[jusfloatin]

I recently purchased this and as I was going thru it I found that there are some wires that there coating is falling off. I was sure it was just a heat problem but it appears that some of the wires are still intact.
The motor runs and runs good but I need to change them which is not a problem as it pretty well straight forward.
I guess my question is why would some deteriate and some would not.

Again all wires are intact it just the coatings are missing or just falling off.

 

[jeff_smith_0423]

Re: 850 Merc.

I'm working on a 850 as well. The coil wires seem to have a much more flexible insulation. The wires for the trigger (violet, white, brown, white/black if i remember it right) have a much thinner guage and poor insulation. I'd take caution working with any of this old wiring. As i've been finding out, these motors suffer from what some call "old merc disease". Basically all of the wiring and insulation has outlived it's useful life.

I believe that a badly deteriorated trigger-finish wire caused the demise of my switchbox. Waiting for a compression tester so i can decide if it's worth the $173 to replace the switchbox. If not, i may have a pile of parts for sale.

 

[Laddies]

Re: 850 Merc.

That is a rather common problem on that vintage Mercs some can be repaired with liquid vinyl or by replacing wires or a combination of the two. CDI Electronics also has a replacement wiring harness available.

 

[jusfloatin]

Re: 850 Merc.

I have used some of that vinal coating but not where heat would be so high.

Am I missing something by thinking that I would just cut and splice new wire in?

 

[Chris1956]

Re: 850 Merc.

Just, You may splice some wire in, however, I recommend you solder it for durability. SurplusUnlimited carries new engine wiring harnesses for about $100