Replacing coil on Tecumseh magneto


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Old 07-19-10, 08:23 PM
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Replacing coil on Tecumseh magneto

OK, so I haven't taken a small engine class since High School so I am a little rusty on what to do here. I've got an old Craftsman tiller that has a 3 1/2 hp Tecumseh 144xxx model engine. It had very weak spark so I thought I'd replace the points and condenser. Afterward, the spark was less yellow more blue, but still felt pretty weak. So I tried adjusting the points again and now there is no spark. Nothing I do will make spark and I did not mess with the magneto gap at all. I am thinking that one of the coil wires leading to the points/condenser is so old and crispy (from age and heat) that it broke inside the insulation and that it's shot.

So I ordered a new coil (since the entire magneto unit isn't available. But it came with the spark plug wire separately, with no ends on it. I'd like any tips you can offer about how to stick the plug wire into the coil (what keeps it in there? Are you supposed to glue it after you push it onto the pin?) and also what the process is to attach the spark plug clip and boot. I assume you thread the wire through the new boot, then strip it, attach the spark plug clip and then pull it back through the boot. But any detailed tips would be really helpful.

It's on my grandpa's tiller and he's 96- still at home but too old to help me out with this sort of thing anymore. Wish he could be young again!
 
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Old 07-19-10, 11:48 PM
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You can glue the new wire in and the plug clip on the end of the wire should be over the entire wire, not just the stripped part. Pull it out and see. I would make sure the coil is bad before replacing it. It takes special tools to set the gap on these.
 
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Old 07-20-10, 06:24 AM
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There is also a little spring that came with the plug wire... what the heck is that for?
 
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Old 07-20-10, 09:36 AM
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It looks like that spring goes inside the boot, but I'm not sure how. And there's another type of metal plug wire connector, so I assume that I should either use one or the other, but not both.
 
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Old 07-24-10, 02:38 PM
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Finally had time to work on the tiller this afternoon and I feel like a man again. Beer 4U2

I ended up throwing away the spark plug clip that looks kinda like a spring, and I used the one that you could crimp around the wire- seemed like the better choice. And then I put some 5 minute liquid epoxy around the wire as I stuck it into the coil. Replaced the fuel line while I was at it. It looks like grandpa used vacuum hose.

Put the coil on the armature, guessed on the point gap, and armature gap, put it all back together and it seems to run pretty well. (surprisingly)

Only thing I need to do now is soak the carburetor, replace the carb gasket, breather gasket, and breather tube. For some reason the breather tube has shrunk back to where it's a bit too short to connect on both ends! No biggie.

It has a little bit of a "miss" to it every few seconds, but I'm pretty pleased that it runs at all!

Thanks for the help Cheese.
 
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Old 07-25-10, 12:57 AM
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Glad you got it, thanks for the update!
 
 

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