The International Cessna^® 170 Association

OK you may recall I recently had a magneto failure and after searching in vain for the parts I needed to repair the Bendix mag I've gone and bought a new set of Slicks with the harness and plugs.

Installing the new Slicks today went pretty well till it got to installing the lower harness. Several of the leads are as much as 10" long despite my best efforts to route them the longest way. I've yet to try up the side of the case under the cylinders and out which I think is the stock method.

I hate it when they are just bunched up in a wad with a tie wrap and I won't do it.

Has any body shortened these ignition wires? I've heard it can be done with a kit and special tools. Is that necessary?

Bruce, I installed my Slicks last year and thought the leads were pretty long also. I first routed them in a way that none were crossed or tangled with each other, then I zip tied them in a tight streamlined fashion on the engine side of the baffle (I hope that makes sense), ran them through the baffle keeping them in a tight bundle, zip tieing and using the brackets where possible to the frame or whatever so that they would not rub or be loose. I wound up with a small loop of slack on the leads that were too long, overall it looks neat and tidy. I will check my pictures to see if I have a closeup. Hope this helps.
David

I checked, sorry no closeups of the harness.
David

N9149A wrote:OK you may recall I recently had a magneto failure and after searching in vain for the parts I needed to repair the Bendix mag I've gone and bought a new set of Slicks with the harness and plugs.

Installing the new Slicks today went pretty well till it got to installing the lower harness. Several of the leads are as much as 10" long despite my best efforts to route them the longest way. I've yet to try up the side of the case under the cylinders and out which I think is the stock method.

I hate it when they are just bunched up in a wad with a tie wrap and I won't do it.

Has any body shortened these ignition wires? I've heard it can be done with a kit and special tools. Is that necessary?

Bruce,
Yes there is a special set of tools to shorten the things. The two primary tools in the kit are a pin vise to install the spring & pin back into the core of the wire and a special set of vise grips with a ring and clamp welded to the end for clamping the shielding shell back to the shielding. I have shortened them with out the special tools simply by using a sharp device to undue the portion that clamps the shielding into the end of the harness lead and then shortening the core insulation and shielding as required. I would experiment with a portion of the excess if you attempt this. After the first time you do it you will see it is pretty simple. After you place the shielding back into the two shells you just need a way to force the two parts back together. A pair of plies to hold the outer shell backed by a bucking bar and a socket to drive the center of the shield clamp does the trick quite nicely.

Regards,
Jim

Thanks Jim. i just spent about 5 hours routing and rerouting the wires to take up the excess without modifying the wire or looping it back on itself.

I need to find an old harness and experiment with it and then next time I'm rerouting stuff in the engine compartment perhaps I'll shorten them.

Yeah. I've got a set of harnesses on my Bendix mags that are too long and were bunched up/tie wrapped. I hate it. I might shorten them someday.