ATC90 Coil

[Frankencelery]

My ATC90 ran beautifully for just a few months after I got the engine rebuilt, then it started inexplicably dying randomly. I kept thinking it was the carb. Then the carb started overflowing, which I thought confirmed it. After dinking around with it forever, I finally found a crack in the float, which was causing my overflowing problem. I include this information in case anyone else has this problem. Check your float carefully!

However, this didn't correct my random dying. I finally thought to check the spark right when it happened and found that it had no spark! I checked the points, which were ok, and hooked my voltmeter to the stator coil and pulled the cord, and it seemed to generate some voltage. The only thing I'm left with seems to be the coil.

Does anyone have any experience with this? I would pull the coil and check the connections, but the coil seems to be buried INSIDE THE FRAME! Am I correct in saying that I have to remove the F!@#!@ engine to get at the coil? Suggestions would be appreciated.

[Frankencelery]

Shamelessly bumping my question back to page one...anyone have ideas how to remove the ATC90 coil without pulling the engine?

[Vealmonkey]

You can sometimes get to the coil if you remove the head frame mount and remove the upper engine to the frame bolt. Also you have to disconnect the frame and the wiring. You should be able to carefull lower the front of your engine down and access the coil. Make sure you support the front of the engine with something, a nice rope would be good.

[MTS]

You got small hands?? undo the 2 10mm nuts that hold it on, pull the airbox off and fish it out, but really, its only 3 bolts to let the motor swing down to get at it, make sure the wire from the points isnt melted/cracked/corroded, (check for conutity) they tend to get run between the cooling fins on them, make sure it isnt just your sparkplug cap too,

[Frankencelery]

Yeah I metered out the wire from the points and pulled the starter...you can see them open and close, so I'm ok there. I think the coil's all that's left, unless you guys think it might have something to do with the wiring in the headlight...? Oh, and I also unplugged the kill switch to make sure it wasn't shorted out.

[vintagemotorsports]

2 things to check first the wires coming out of the stator common for them to breal right after the grommet in the case , if ok you probably have a bad condensor coils dont let go that often condensors do , only problem is its bolted to the coil , pull the engine it will save you time in the end screwing around trying other ways , make sure you have a good ground also between the engine and the frame Mike

[Frankencelery]

Stator wires seem ok, and when I connect to the output and pull the cord, I get a spike, so I think that's ok. The problem is intermittent though, so I'm not sure where it's coming from, but I'll check the connections to the coil and replace the condensor before I do the coil. It'll be this weekend before I get a chance to look at it.....

[Frankencelery]

Ok, I got the coil out. Something was keeping the engine from swinging down and giving me enough room to pull the coil out, so I ended up pulling it out through the air filter hole like someone else suggested. Turns out the condenser was shorted. My local small engine shop found me a suitable replacement, and today I got it all back together and running perfectly! My son and I rode it around in the snow this afternoon. Thanks to everyone for their help on this!