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Discussion Starter #1
I just bough 3 more Gravely's and now have 4 L's. They all have Wico Mag's. I've always worked on the more modern points, condensor and coil engines and I am new to magneto's. The parts for mags are much more expensive and I hate to spend more than I need. The first one I started working on hadn't been started for many years. I cleaned the carb and gas tank and checked for a spark. I had a spark but not sure how hot is was. I put a little gas in the cylinder and it didn't fire. I suspect a weak spark but hate to just start putting in coils, condensers and points or what ever else a mag needs. Is there a way to diagnose a problem with a magneto?
 

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These mags are pretty simple. If you're making a spark at all, it's likely that the coil is ok, and probably the condensor too.

One of the most obvious things to do/check, esp on one that's been sitting a while, is to clean and gap the points. You can get in there with a very small file, or even just pull some emery paper between the points when they're almost closed. I've had good success doing that kind of simple maintenance on several mags.

Just make sure you get everything clean afterwards. You don't want crud rattling around in there, and you don't want to leave oil or grease on the surfaces of the points.

Note also that the mag could be fine, you could have a bad wire, or plug. A bit of swapping around of those components will tell you whether it's the mag or something else.

Good luck, and :wwp:
 

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Discussion Starter #3
These mags are pretty simple. If you're making a spark at all, it's likely that the coil is ok, and probably the condensor too.

One of the most obvious things to do/check, esp on one that's been sitting a while, is to clean and gap the points. You can get in there with a very small file, or even just pull some emery paper between the points when they're almost closed. I've had good success doing that kind of simple maintenance on several mags.

Just make sure you get everything clean afterwards. You don't want crud rattling around in there, and you don't want to leave oil or grease on the surfaces of the points.

Note also that the mag could be fine, you could have a bad wire, or plug. A bit of swapping around of those components will tell you whether it's the mag or something else.

Good luck, and :wwp:
Thanks! Glad to hear that most likely the coil is ok. I will try these thing this weekend. I haven't tried a new plug yet. I know the champion W14 is not available now and trying to get a Auolite 3067 I just got to travel a few miles to a bigger autoparts that carries that plug.
 

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For starters I'd just try swapping plugs and stuff with one of your other Ls.
 

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Once you've cleaned those point good, pull a dollar bill thru them when closed. There are spark testers that can be used to test the mag. Stihl makes one as do a number of other companies. An adjustable gap tool is is the cheapest way to check. Bright blue-white spark across a 3/8" gap is a good mag.
 

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Discussion Starter #6
Once you've cleaned those point good, pull a dollar bill thru them when closed. There are spark testers that can be used to test the mag. Stihl makes one as do a number of other companies. An adjustable gap tool is is the cheapest way to check. Bright blue-white spark across a 3/8" gap is a good mag.
Thanks! This forum is great for info. I think I've become a Gravely junkie now. An interesting note. I have a great friend that I've known for nearly 20 years and just found out that he grew up in West Virginia. While he was in college he had a part time job with Gravely in Dunbar testing Graveley's. They would give units to a few college students and let them lose trying them out in extreme conditions and rough terrain. They would try hard to break them so they could take a break while the next unit came. He said, sadly though, it was difficult to break them. Quite a testament.
 
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