Problem with bike running (electrical or ignition?)

[shuohan]

Hello,

I have a strange problem that I haven't been able to pin down. I was riding my bike last night, 1989 ninja 250, and it was running great. Suddenly the engine sputters and stalls. I pull over and try to start the bike but nothing, the starter doesn't even crank and the headlight shut off. However, my gauge lights are still on and my brake light still works. I get a jump from a friend and the bike runs again. Then I hear some backfiring and soon my bike stalls again in the same fashion as before.

The bike will sometimes start if I wait a long time but once it starts it idles very poorly. If I try to use any electrical equipment like the brake light or turn signals, the idle will be interrupted and the bike will stall. Today I had a chance to work on the bike a little bit and test the battery voltage. It was 13-14 volts unloaded and no less than 10-11 while cranking, maintaining around 12-13 while running. I also tested with only a known working car battery (bike's battery disconnected) connected and the result was the same.

I tested the bike again with no lights hooked up. Even then, the starter would only sometimes crank after given a break. Upon the starter moving, I had to give some gas to get the bike to start or sometimes apply choke. After it starts and idles the idle fluctuates in RPMs. I was able to kick it in first gear while holding the RPMs high and ride it forward a bit. Basically, the bike just runs really really bad, completely different from right before whatever it was "broke". She was running perfect before it sputtered and died last night. It seems to me like an ignition or electrical problem. Does this sound like a bad stator/rectifier/regulator?

I hope I'm not stuck lugging her down to a cycle shop for diagnostics. I hope somebody has some idea on what to do. Thanks in advance.

[AK82kz440]

Ran into an electrical problem my self a while back. Was sent this like by someone from a different forum. Helped me might help you too!!

https://www.electrosport.com/electro...t_finding.html