Battery, Stator, Rectifier? Something else? Stalling issue


2000 with 12,500 miles, all stock.

Bike stalls after getting warmed up if left idling. I can ride it for 10-15 miles but can't let it sit for more than a minute or so after it's hot and he fans have cycled.
I hooked a meter to the battery during cold start and I get 13.3-13.5v. As the bike gets hotter, the volts drop to ~11.5. It's at that point it starts sputtering and will eventually stall.

Thanks for any help you can provide.
Seeing as you have 13 volts on start up, them your battery voltage goes down I'd suspect a problem with the rectifier. I've had them go bad before. The earlier years of hayabusas have had issues with the plugs on the rectifiers burn up on them. It be worth taking the tail off and inspecting the connector. Also while you have it out, and you have a meter you can test the phases in the rectifier. Test on ohms 1-2 2-3 and 3-1 and you should not read open. If you so it's the rectifier. If all of your cables are in good shape, then you should start inspecting the alternator. Testing should be the same as the rectifier. Verify with your manual first, you might have to check that with the bike running but I doubt it.
Thanks for the reply. It's weird. I could ride the bike forever without issue but I can't let it idle for more than 5 mins.
The Gen Is don't like to sit and idle, stop and go traffic is a killer. Number one stop the 5 minute idle business, number two before you buy anything, how about checking all your connectors. The rectifier connectors are known for melting. If everything checks out then find a free service manual online and start looking at the troubleshooting guide or testing the charging system.

When you crank your bike it's gonna drop the battery voltage. A Gen I at idle does very little if any charging. The 13 volts is great, at 5000 RPMs it should be between 13.4 and 14.4 from memory. Get the service manual.
I would strongly suspect the voltage regulator. It is normally pretty hot - not from the engine, but from reducing excessive electrical load - the less electricity the bike is using, the more power voltage regulator needs to burn in order to preserve almost constant voltage. So, when you start the bike, the voltage regulator is still cold and performs OK. In a few minutes, it warms and starts working poorly. When I had '01, it started going South as I noticed my voltage during rides started dipping to 12.0-12.5V. After I replaced the regulator with an aftermarket one, all went back to normal. You can follow the service manual to troubleshoot.

There is another potential problem - stator connector, with 3 yellow wires, under the rear part of the tank. Over time, oil pressure inside the stator may push oil inside the yellow wires, ultimately pushing oil inside the connector. This connector transfers the most current among all connectors on the bike, and therefore is very sensitive to the slightest poor connection. Even under the normal circumstances, this connector is warm from a strong electrical current flowing through it. Lift the tank, start the bike, and let it idle. Keep touching this connector every few minutes. If it gets warm and stays warm, you have nothing to worry about. If it gets so hot that you cannot hold a finger, you've got a problem. Open the connector, and see what's going on. On my '01 it got so bad that the excessive heat destroyed the entire connector and turned it into charcoal - when I opened it, it crumbled in my hands.
Good info above! I had an '04 SV1000S earlier in the year and the bike ran fine but it got to when I hit the turn signal button the engine would die. I was told by a professional that it was the stator and/or rectifier beginning to go out.
Does your turn signal kill your engine?
This was a bike that was only about 9 years old so I would say your bike is old enough to start having issues.
Sounds like Ig is on to something with his experience with the regulator but if I ever had to replace the rectifier I would also replace the stator at the same time too!

If you know you want to keep the bike then it would be worth it to spend a few hundred bucks on it oh and also a service manual is also a "must do - no brainer" if you're keeping your bike. The reason I say keeping your bike so much is because I thought I was keeping my SV but once I learned more about Hayabusa's I then knew I was sinking money in the wrong bike so I traded it in. :whistle:
Ok, put a new battery in and started it up. The battery was ~12.6 with the bike off. However, when I started the bike up, on idle, it stayed around ~14.3. Eventually, the bike stalled again but this time with little to no voltage drop.
As I cracked the throttle the voltage DROPPED. Is that normal? When the R's came down the voltage would go back to 14+ volts
I pinned out the rectifier and everything checked out okay. It had no visible signs of wire fatigue.
Any more thoughts? With an idle of 14+ volts I would think that eliminates any stator issue.
Did you check the stator connector for being hot? As you rev the engine, the stator increases the current, and in case of poor connection more voltage is lost on such poor connection, thus leaving you with less voltage going to the battery.

If the stator connector is not hot, then I'd say 90% it's voltage regulator - very consistent with what I observed on mine - voltage went lower when revving up.

You have to pursue the issue consistently and logically. Otherwise, you won't be able to make the right conclusion, and end up guessing and replacing unnecessary parts.
My bike does this too...I am looking at testing the parts here soon so I know what I need to buy this winter. Mine isn't to the point of killing the bike....yet.