KA100 Wiring Harness/Start Button

Maintenance, Repair, Equipment & Tools
1

I read somewhere that the KA100 has an issue with the start button. After just a few months, it seems as though our button has gone out. It started with working intermittently, but seems to be out completely. I took the button, and everything looked to good. I cleaned the contacts, but when I put it back together, it still did not work. I have the direct power transponder, and the way that reacted when I pushed the start button, I think I have a short in the KA100 wiring harness. Has anyone had experience like this, and if so, what was your fix for the problem? I don’t want to spend the money for a new harness if I don’t have to, but if there is no other option, I’d like to know. TIA

2

The wiring harness for a KA rather simple. I’d start out with a visual inspection of the harness. The start button completes the circuit to the starter. The kill switch grounds the coil. If you don’t have a multimeter, you can pick up a cheap one at a local hardware store or on online. Ohm out the start button to verify if it’s working. Then ohm out the harness. If all the wiring checks out OK, check for a missing ground or a broken brush in the starter.

If you have an external starter, you can use that and you don’t have to have the harness.

3

Thanks. I was going to look over the wiring before our next race. I used our external starter at the race last night. I don’t think it is anything to do with the starter since I just got it back from being rebuilt, and the issue started before sending it in, but still worth a look to rule it out.

4

The symptoms you describe are very similar to worn starter motor brushes, I would give them a check too. I have seen a few issues with KA 100 wiring harness’s but would think the more likely cause would be brushes.
Easiest way to check between harness/button and brushes, would be to run a positive wire direct from the battery to the starter power wire and see if the starter kicks over. If it does, the fault is in the harness.

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5

Just a quick follow-up. Thanks for the tips. I checked out the wiring harness with an ohm meter, and all aspects checked out good. I took the starter apart, and the brushes looked fine. Come to find out, even though my battery showed 12.4v, it was bad, as was my spare batteries. Probably just a issue with SLA batteries in heat and vibration. New battery on it’s way.

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6

Thanks for posting your solution

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