Help with electric start project please

[adamz]

I have a 2016 Polaris switchback assault with electric start. I decided to attempt to create an electric start system similar to the new Ski-Doo SHOT system that uses supercapacitors to start the engine. It won't be completely like the Doo system since my sled still has a starter motor but regardless, it will save weight and be cool. First, I plugged in the uncharged supercap setup in place of my battery and pulled the sled to let it run for a few mins to charge the caps up. Tried to start, nothing at all. Decided to charge up the caps to approx 12.5v using the battery and then hook up to sled and try again. With this setup, I was able to hear something cranking and spinning around (assuming the starter motor), but the engine would not start. To make sure I didn't mess anything up, I then tried the electric start with just the battery and it fired up no problem. Any ideas what could be wrong? Why the sled didn't charge up the capacitors? Why the motor would spin but sled doesn't start? Thanks.

 

[Murph]

With a battery installed---a spinning E-start motor without engaging the ring gear behind the primary usually indicates a weak battery, or worn starter motor. There is not enough amps to hit the starter hard enough to spin the flex shaft fast enough to allow the bendix in the pinion gear to throw itself towards the ring gear.

Looks like you are using small gauge wire on those caps. Probably can't deliver the amps required to spin the archaic starter motor.
I would try with 6-8 gauge wire and see where you are.

 

[adamz]

With a battery installed---a spinning E-start motor without engaging the ring gear behind the primary usually indicates a weak battery, or worn starter motor. There is not enough amps to hit the starter hard enough to spin the flex shaft fast enough to allow the bendix in the pinion gear to throw itself towards the ring gear.

Looks like you are using small gauge wire on those caps. Probably can't deliver the amps required to spin the archaic starter motor.
I would try with 6-8 gauge wire and see where you are.

Will do, thanks!