Kawi2strokes.com Forum

I now the '72 H2 can make spark with no battery. Will it harm the electronics if it is run without a battery installed?

The manual says it will eventually damage the stock CDI units. I believe this is because the two magneto windings produce more voltage when there's no load from the battery. On my test rig I can see the sparks get brighter if I disconnect the regulator, for example.

If you want to run without a battery you can connect a fairly large capacitor in place of the battery and it'll be fine. I put 22,000 uF 25v capacitors in the regulators I make, and that does the job. They're not expensive from places like www.mouser.com

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If it surges, that's normal, upshift.

I will have a battery this week, I just wondered if I could run it for a minute or two for an initial check till I get the battery in.

2 seconds may spike it.

Why hurry?

Listen to Jim (sparky)

cliff

2 seconds may spike it. 400 volts floating here and there.

Iggy and charging bat. are 2 "separate' systems, but ...

Why hurry?

cliff

To do that, disconnect the regulator and short the two yellow wires from the alternator together. You can make a jumper to do this if you have a couple bullet connectors. This will not cause any extra stress on the alternator because it's a permanent magnet type.

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If it surges, that's normal, upshift.

Thanks for the replies. So far I have kicked it over with the plugs out to check for spark on all 3 cylinders.
Run will wait for the battery.

Hi Jim,
Is it feasible/worthwhile to wire two or three capacitors in series? I'm looking at an e-bay auction and they are selling (6) 22,000 uF 25v for around $30.

Putting two capacitors in series results in half the capacitance and double the voltage rating. I don't think that's what you're after. Two in parallel will double the capacitance with the same voltage rating. You could do that but I'm not sure it will give you much benefit.

Aren't you running one of my regulators? Just curious, since you've bought them in the past.

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If it surges, that's normal, upshift.

Hi Jim,

Yes I am running your regulators. Just a general question, maybe for RD400 project bikes. Thanks for the info, I can solder but I don't know much about amps, volts, capacitance etc.