Strange Electrical Issue - No spark unless gas pedal is pumped

[Timberwolf530]

I have an early '90s Yamaha cart I am working on . From what I have been able to gather from research, it appears to be a g8 or g9, though I am not 100% sure of that. Recently, it stopped charging the battery, so I replaced the starter/alternator, and the battery. Nothing had been done to this cart for years as far as parts or repairs. Just yearly plug and oil changes. I found that the plastic carb spacer was cracked, so I replaced that & figured I would change the carb while I was at it. After I put it back together, it would not fire. I found it was due to no spark, so I tested the coil. It tested out of specs, so I replaced that. Now when I crank it, I get no spark unless I am pumping the gas pedal as it cranks. I get a weak spark then. It still isn't enough to start, but if I stop pumping the pedal, no spark at all. I bypassed the pedal switch, thinking that might be it, but that had no effect. I've never seen anything like this before. Anyone got any ideas?

[CP241]

I'd double check power and grounds at the ignitor. Did you use an OEM coil or an aftermarket one? Most of the aftermarket coils are junk. OEM ones are expensive, but work.

Also these are known to occasionally have weak grounds in general. You could try grounding the engine block to the negative battery terminal and see if that makes any difference.

[1arunem]

I had a VERY similar issue on a G16, would only spark when pumping pedal. Turned out to be a bad ground going to the solenoid (small neg post).

Maybe check that and the engine stop relay..


Good luck.

[Timberwolf530]

Aftermarket Coil, but it tests within specs on the meter. What is wrong with them? Where is the engine stop relay.

[1arunem]

I am not sure on a G9. On the G16 it is next to the solenoid.