Reply To: No spark – GT250 Carby
Evening,
I thought I would bring the problem solving for the spark issue back to the Tech Help section so as to help any others that may have a similar issue in future (as opposed to the Project thread I have).
I had a chance to check the 3x yellow wire plug (Charge coil). I got 109 ohm. Spec tolerance 90-110 ohm. So ok there.
The Blue + Green wire plug (pick up coil). I got 0.6 ohm. Spec tolerance 0.6-0.9 ohm. So ok here as well.
I hadn’t seen your post Marcel so have’nt taken the stator cover off for a photo. I’ll pop it off next time I’m in the shed. I had already sort of checked the CDI/loom, but I only checked using the continuity function (the buzzer), not the resistance like you mentioned. Is chekcing with resistance better?
Using the buzzer there doesn’t seem to be any breaks in the loom and the wires align with the wiring diagram (mostly). I’m getting continuity from my CDI to all of the key components regarding ignition/spark. Likewise for the regulator rectifier.
I tried my replacement coils but that didn’t solve the issue, so back to the drawing board.
I tested the rear ‘brick’ diodes with the 3 wires (Blue/yel, Blue, Green/red) and came up with the following readings on the diodes;
- B/y = 0.512v
- B = N/A (signal to CDI)
- Gr/r =0.576v
I opened up the mystery black ball thing which had a yellow sensor (?) thing and 2x diodes. It has 3 wires (Black/brown, Black, Black/white) and testing them I came up with the folling readings on the diodes;
- Blk/brwn = 0.190v
- Blk = 0.185v
- Blk/wh = NA (earth from yellow brick thing, to earth for rear coil)
When I carried out a buzz test on the 2x diode wires, they colour match 2x black rubber covered plugs that pop out the front of the frame and buzz. They almost look like wires for a horn but they don’t align with the colours on my wiring diagram for the horn. Being a race bike all road items (horn, lights, indicators etc) where removed and I can’t find the corresponding plugs – could they be for a 2x wire indicator relay? I’ve had them before but the wiring diagram shows a 3x wire relay at the rear of the bike. These wires are at the front.
I carried out a resistance test on the CDI using the pin table in one of the manuals I found on this forum. I’m not getting a single match. For reference, my multimeter is auto ranging.
My next steps are to borrow a CDI off a known running bike and take the cover off the stator for a photo. Failing those, I’ll try source another loom/harness.
Any ideas people?
