Coil testing (Solo 637 TH)

[rmihalek]

I think the coil on my Solo 637 top handle saw is fried. It's not getting spark, even with a brand new plug installed. I checked the wiring and don't see any broken or bare wires.

I'm wondering how I can check the coil to see if it's functioning?

If it ends up that the coil is bad, does anyone know of a replacement for it? Bailey's wants $90 for a new coil. If I can identify some other coil from another model that would fit, I might be able to buy it at an auction site/craigslist.

Thanks in advance for any help.

 

[Stihl-Pioneer]

Did you take the wire off the kill switch and recheck or just inspect the wires? If you didn't unhook the wire do that first. Also check the ground wire for the coil isn't broken.

 

[rmihalek]

I put a multimeter on the coil and various components and discovered that the wire from the coil to the spark plug was bad. Upon closer inspection, there was very small abrasion where the wire wraps around the cylinder on it's way to the top of jug and that was enough to short it out.

I put a few wraps of electrical tape around the spot that wore through and the saw fired right up. I'm sure the tape will wear out pretty quickly, so I'll need to come up with a longer term solution.

I contacted Solo to see if coils from any other saws fit on this saw so maybe I can salvage one from a seized saw or something like that.

 

[Gushh]

Try to push the sparkplug cap out and push the wire in, so you get the spring connector exposed. it usually goes "crimped" (it just punctures through the high voltage wire) so you could remove it if you wanted to at this stage.

Now that you've got access to the bare wire, you can use a non acid silicone to repair the gash and heatshrink sleeving / tubing to repair the insulation, 3-4 layers worth will be as good as the original and won't leak much voltage out at all.

Of course, it won't beat a new replacement... but until then, why not?



I'm not a fan of electrical tape, or duct tape... or that kind of stuff :msp_sneaky:

 

[Hunowie]

All solo 640-633-637 have same problem the wire is touching cylinder and cut at that spot. You have to tie wite to the cover. i used some metalre and 1mm drill. Its holding so far.

Is the 637 coil limited?
What about older 633 and 640?

^^ 633 is really nice, I'm looking for 201t to race^^

 

[Gushh]

To repair what Hunowie mentions you should remove the cap, slide some heatshrink sleeving on, shrink it, slide another layer, shrink it. then finally reattach the cap and use a ziptie to hold the cable in place so it won't rub onto anything metal, if you also heatshrink your ziptie you'll have a very durable fix, otherwise the ziptie would also cut into the wire insulation but as long as it's not touching anything metal the losses shouldn't be too high, but there are losses after all it's an HV system we're talking about.

 

[rmh3481]

Bob,
Try a short piece of 'wire loom'. Its made for this and is slit down the side so you can get it on and off.
http://www.bing.com/images/search?q...CA52177E9B151C67FC15E81097DEF2F6D&FORM=IQFRBA

 

[Gushh]

You use what you have, if you're going to buy anything go buy the spare for the actual damaged part. As far as looms go use fibreglass weaved then, not plastic.

 

[redfin]

Won't the wire disconnect from the coil?

 

[Hunowie]

You are right about the ziptie and using sleeving. In the633 im doing today wire had a ziptie and wasnt touching cylinder and yet was cut by the plastic part of the starter.
Some non plastic sleeve wiuld be best.