Author Topic: AC or DC  (Read 997 times)

Vivo

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AC or DC
« on: June 15, 2013, 08:25:10 AM »
I had a scoot with an AC fired CDI... If the battery is very weak, you can kick start it easy... you can even start the engine without a battery using the kick start...

My Kymco has a DC fired CDI... If the battery is very weak... you are doomed because you need the battery to power the CDI...... now what is the purpose of that lever at the side called a kick starter?

A lot of new bikes, even small bikes, have the DC fired CDI... why change something that aint broken?  What are the advantages of a DC CDI versus the AC CDI?   
« Last Edit: June 15, 2013, 08:31:56 AM by Vivo »

CROSSBOLT

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Re: AC or DC
« Reply #1 on: June 15, 2013, 05:15:26 PM »
I am not ignoring you, I just do not know. I may have lots of company! The 60s Hondas could be wired to use the "dynamo" for a magneto. It would make sense to have the AC system since it would allow a near dead battery start. Dunno about the "advantages" of the DC setup except maybe for the manufacturer.

Karl
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

blue

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Re: AC or DC
« Reply #2 on: June 15, 2013, 09:22:29 PM »
I had a scoot with an AC fired CDI... If the battery is very weak, you can kick start it easy... you can even start the engine without a battery using the kick start...

My Kymco has a DC fired CDI... If the battery is very weak... you are doomed because you need the battery to power the CDI...... now what is the purpose of that lever at the side called a kick starter?

A lot of new bikes, even small bikes, have the DC fired CDI... why change something that aint broken?  What are the advantages of a DC CDI versus the AC CDI?
ya my scoots the same way dont care for it but I just make sure my battery is in good shape all the time.

MotoRandy123

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Re: AC or DC
« Reply #3 on: June 15, 2013, 09:25:07 PM »
Just thinking out loud, once you go to fuel injection you need the battery to start anyway
so why not make the DC coil larger for more juice and eliminate the AC coil (because the big DC
one is taking it's place on the stator). A typical car is all DC and the bigger scoots and bikes emulate
a car setup....
2012 Yager GT 200I - Southern NH

blue

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Re: AC or DC
« Reply #4 on: June 15, 2013, 11:23:08 PM »
my other scoot I just by pass the fuel injection and did cravty flow by takeing the pedcock off and replace with a open valve to flow the gas right to the carb. that way you can by pass the elc. choke and the emission con. works great on my little scoot.

Vivo

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Re: AC or DC
« Reply #5 on: June 17, 2013, 01:28:06 AM »
@ CROSSBOLT:  Maybe you're right about advantages to the manufacturer...


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