Hi all, new member here but long time rider of 55 years. I have had a 99 Drifter 800 for a while but recently this problem popped up.
The bike has always fired up right away and runs smooth as glass. Recently it fires up cold 99% of the time and runs great. However if it runs even a very short period time as in a minute or two and is shut off, when attempting to restart the bike it has no spark and will obviously not run until the bike has sat for quite a spell and cooled off completely. I have tested everything I can with a multi meter, connections etc. There are no wiring mods done so the harnesses etc are all in clean oem condition. When it starts it does not die and seems fine, until it's shut off. When running it's charging at 14.3 or better, weird thing I think is it charges at that level at idle and seems to drop a bit at higher throttle openings. A note or two here as well, the rectifier gets damn hot fairly quickly, but I'm not sure what's normal or not. All fuses are good. I can't check the ignitor as it says using any multi meter other than the Kawsaski version can damage it. I have checked all grounds, handle bar switch, side stand switch and all appear to be fine. Hopefully someone on here has faced the same issue. any help would be appreciated.
Load test your battery.
What Bucko said + 1.
I've had that kind of problem, a couple of times and each time it sorted out that the battery was in bad conditions: so, I just replaced it and everything went great...
New battery, and also swapped the battery out of my other drifter, same results. but thanks anyway.
new battery, and swapped the battery out of my other Drifter, same result, but thanks anyway.
The engine cut-off switch, IE kill switch, and the side stand switch are both suspect.
Quote from: Bikes Are Life on September 29, 2025, 17:20:03 PMnew battery, and swapped the battery out of my other Drifter, same result, but thanks anyway.
It's probably not your battery if it's new, but I've had a bad new battery before, so may still be worth checking with a load test. If you don't have a load tester, you can do a simple check of comparing static voltage to voltage while cranking - if it drops more than a few volts, the battery is suspect.
I finally figured out the problem with my bike. After many hours of tracing circuits, testing components, swapping out components from my other drifter. It ended up being the TPS. I disconnected it and problem solved. Swapped it out with one from an old drifter carb and the bike is running fine again. Not that anyone is interested, but just an FYI.
Makes sense. The TPS is used to control spark timing.