Generator used as electric starter

Electrical issues
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Generator used as electric starter


Post by DuoDave » Thu Jan 22, 2004 5:52 pm

Why can't a generator equipped bike use it's generator as an electric starter? I realise that if it was simple, the manufacturers would have done it decades ago, and that stock Panhead components aren't suitable, but I'm told that on Volvo boat engines and in the N.S.U Prinz car, the generator doubles up as the electric starter.
I'm just curious to know the technical reasons why this isn't done on bikes.

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Re: Generator use for electric starter


Post by haggis » Fri Jan 23, 2004 1:16 am

Duo Dave,
thought about your of the problems I can see is Torque, trying to spin the motor from the generator gear ,( which is tiny compared to the starter ring on the clutch hub) would mean the gen' would have to be cranking like a mofo.....and drawing a zillion amps too.
The idea is sound though, but probably has a pile of engineering requirements drive gear swapping , gear box reduction and a host of electronic wizardry.
just my 10 cents, Haggis

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Re: Generator use for electric starter


Post by Sidecar » Fri Jan 23, 2004 10:34 pm

Probably the most important killer of this was that everyone wanted to get away from genny's and jump into alt's. Genny's are big and cumbersome and have a low power output. The "big" guys wanted alternators.
I have seen starter gennys on bikes, boats and tractors. Most of them seem to work well.
Another might be that H-D wasn't in the lead for developing state of the art stuff.
You'd need a MUCH larger battery than you have now to turn the starter.
Not enough money in it either. If someone designed one to do it, I don't think that they could sell enough of them to get the cost down. You'd have to sell your scoot to be able to afford the starter/genny.
I think you'd find that the ones that are in service have motors designed for using them.. Not an afterthought.
Ural motorcycles yanked their genny's and tried the starter/genny thing and it didn't work out too well.
I believe that it would have to installed in a different location from where the gennys (in H-D's) are installed now.

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Re: Generator use for electric starter


Post by john HD » Sun Jan 25, 2004 3:42 pm

they just don't have enough power
when i bench test my generator by making it run as a motor you can stop it with just your hand.
even in tip top shape they are not that powerful!


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