ATV electronics help

Thread Starter

robismod

Joined Sep 22, 2015
217
I’ve had no luck posting this on ATV sites, so I thought I’d try it here…
I acquired an 87 model Honda ATV that sat for years and has no spark. I traced anll way back to the alternator/stator, and have out in the bench now…I believe there are two coils that are wrapped in black that are paired together, and about 6 more unwrapped, tied together. I’ve been confused on instructions to test…I think the two black ones are “open” and that’s why I’m not getting spark…the other coils seems fine and supply charging for battery etc. from my understanding…
Anyone offer a little more guidance?
 

debe

Joined Sep 21, 2010
1,389
Here is aprox ohm readings on the HV & Pulse coils. Also simple circuit i use for checking for voltage from these coils at cranking speed.HON46.jpgPEAK VOLT ADAPT.JPG
 

Thread Starter

robismod

Joined Sep 22, 2015
217
Here is aprox ohm readings on the HV & Pulse coils. Also simple circuit i use for checking for voltage from these coils at cranking speed.View attachment 291327View attachment 291328
Thanks very much for those drawings. I’d like to put one of those Peak Volt adapters together soon. But last night, I found a repair manual page (for this TRX125 engine) that detailed testing of the “alternator exciter coil” and my meter test showed nothing where the manual called for “100 - 300 ohms”. That was testing between the Black/Red separate wire and ground…
 

Thread Starter

robismod

Joined Sep 22, 2015
217
Last night I tried to clear out as much of the black, rubbery coating that covered the terminals associated with the two coils, and could see a fine wire or two somewhat. Best I could tell there was no continuity between two solder posts where the wires looked to end up. But there was continuity from that side of the unit across to the other side, to the contact post where the signal is sent out by a wire to the pulse generator…so I think bottom line there’s a break in the coil windings between the two coils…arrrrggggg
 

debe

Joined Sep 21, 2010
1,389
If all else fails, this is what i built to power a CDI unit on a small generator, the HV coil had failed. The transformer was a small mains 240v to 20v center taped. It worked fine at 3000rpm, but dont know if it will go higher as i didnot try it.CDI.2.JPG
 

Thread Starter

robismod

Joined Sep 22, 2015
217
If all else fails, this is what i built to power a CDI unit on a small generator, the HV coil had failed. The transformer was a small mains 240v to 20v center taped. It worked fine at 3000rpm, but dont know if it will go higher as i didnot try it.View attachment 291379
Wow! That’s cool as ever! Maybe I’ll get the time to get back to spending time at the bench—since I married and moved to her place in the mountains, there’s a whole lot of STUFF around here to tinker/fix/maintain, etc…and a recent 48 days of radiation and hormone therapy for prostate cancer have done a number on this tired body…hoping to be bouncing back a little more lively soon…
 
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