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The 2-Stroke Garage => Turning Wrenches => Topic started by: ElFuegoBlanco on August 26, 2022, 10:32:01 AM

Title: Ballast resistor bypass for new coils
Post by: ElFuegoBlanco on August 26, 2022, 10:32:01 AM
I picked up some new coils from Economy and the product description states:
"We recommend removal/bypassing of ballast resistor on RD400's"

I just want to make sure I have this right. I'm going to connect the existing male red/white wire from the loom to both black wires on the new coils, leaving the three resistor wires disconnected. Then connect the yellow wires on the new coils to the corresponding orange and grey wires on the loom.

Can anyone confirm or correct me?
Title: Re: Ballast resistor bypass for new coils
Post by: m in sc on August 26, 2022, 10:41:42 AM
THATS CORRECT.
Title: Re: Ballast resistor bypass for new coils
Post by: ElFuegoBlanco on August 26, 2022, 12:28:03 PM
Quote from: m in sc on August 26, 2022, 10:41:42 AM
THATS CORRECT.

You're the man, Mark.
Title: Re: Ballast resistor bypass for new coils
Post by: Clem710 on August 29, 2022, 06:02:02 PM
Is this SOP for old coils as well? SV coils? Anybody know the reason behind it?  New coils higher ohmage?
Title: Re: Ballast resistor bypass for new coils
Post by: m in sc on August 30, 2022, 10:04:53 AM
sv coils also are straight wired. the stock 400 coils are lower and need the external resistance. thats it.

Title: Re: Ballast resistor bypass for new coils
Post by: Clem710 on August 30, 2022, 03:20:10 PM
Thanks for the explaination.

hmmm, I may need a low ohm for some testing on a 6v, no battery, points scoot and the 400 is down anyway...

IIRC, chinese scoot coils are real low primary, 1 or less? and about 6k secondary, SV spec is 3-5 and 25k iirc.

I will probably try an SV for science but I think my spec is 1.5 and 10k so might not do a whole lot, we'll see

Title: Re: Ballast resistor bypass for new coils
Post by: m in sc on August 30, 2022, 03:39:50 PM
thats because they are for a cdi

Title: Re: Ballast resistor bypass for new coils
Post by: Clem710 on August 30, 2022, 07:05:39 PM
Well, after how many years, I finally understand why you were suprised that SV coils were high.

Never really looked into specifics for coils, just tried to mach em up close. Know way too much about em now:)

On the plus side, I think these 6v ones are mostly down around 1 so it shouldnt be a problem to find one to test with.

I suspect carburetion as the primary suspect but while its apart, may as well check everything and get it as good as it can be :vroom: