Trouble Getting Started

We purchased the bike confident that it runs easily with the kickstart. But, like my old '73 Aermacchi Sprint 350, whose the starter motor was temperamental, this one just didn't work.

And so began the methodical process of troubleshooting…

04.24.20 This started with charging the tractor battery that the bike came with, which took about 40 hours to fully charge. The contacts were cleaned as well, so with that variable now out of the equation, we looked to the starter relay. 

04.26.20 We opened up the start relay to discover that it was manufactured by Bosch. Upon inspection, it looked to be in near perfect condition. ​There was some corrosion on the contacts which we removed with some fine grit sandpaper. It was reinstalled onto the bike and with the starter button pushed, we could hear it clicking. It was working like it should! What else could be the problem?

Further along the chain, it was time to inspect the Nippon Denso starter motor itself. We pulled the cover off the starter motor. Brushes looked good. Commutator looked good. Then we pulled the motor out of the housing and inspected each of the pads on it to make sure that there was no crossover current. Everything checked out in the tedious inspection.

So we hooked up the starter motor to the bike, with it out of the housing and it spun. Starter motor works.  

What wasn't working, however, were the planetary gears behind the start motor. The teeth on the gears appear to have been destroyed. Assuming one of the teeth broke off and wreaked havoc, thereby causing damage to the other gear teeth, including the ring gear. What a hot mess.

Note the shards of metal gear teeth in the grease!