Ran when stopped

LeftyKash

XS650 Enthusiast
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Last week on my way back from AMA Vintage Days I pulled into a gas station, hit my kill switch, turned off the bike and filled up t he tank.
After gassing up the bike would turn over, but it wouldn't even try to start. The voltmeter off the key switch showed more or less 12v. I didn't have much for tools, but I took the kill switch out of the circuit, thinking maybe it had gone bad. No dice. I had recently switched to a gonzo TCI, as my OEM one was cutting out intermittently. Since the old one was still on the bike, I plugged it in. The engine tried to start, ran really rough, but wouldn't idle or rev up at all. I gave up and called a buddy with a truck to come get me.

Once I got home, I checked the plugs, they looked ok. Plugged in my spark checker, no spark.
Checked resistance on my coil secondary ~24k ohms ok.
Checked resistance on coil primary 2.8ohms OK,
Checked the pickup coil, 750 ohms on each side, 1500 ohms between them. OK.
On a whim, I opened up the LH cover, and found that the magnet that the PO had put on the rotor had given up the ghost.
I'm not 100% convinced that it is the only issue, but once I wash all the Vintage Days dirt and mud off the bike, I'll pull the rotor and repair.
1658914870864.png

It was a hot weekend and I'd been riding the bike a lot. It ran perfectly all the way to the gas station. I'm guessing that once I stopped to gas up after that long ride, the adhesive picked up just enough heat to let go. Who knows for sure though?
 

LeftyKash

XS650 Enthusiast
Messages
38
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73
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Location
Columbus, OH
Magnet is definitely gone but I uhhhhh, can't find the old one?
PXL_20220727_190802019.jpg
I looked all over the rotor/stator area. I even removed the pickup coil and timing plate, thinking that the rogue magnet might have stuck to the back of a bolt.

Anyway, I filed down the old adhesive, cleaned it off, and then jb welded a new magnet on there. You can see some scoring from where the old magnet made it's final flight, but I think it'll be ok.
PXL_20220727_191540743.jpg
 
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