Hope u guys can help me, see you have been talking about coil and rectifier problems. I live in Sunny South Africa and have a NSR 250 MC21, by the way this website has been a great help in the past.

My bike does not charge the battery when the lights is on, and out here we have to ride with our light on. Have replaced battery and checked my rectifier/ reculator on another bike, both are fine. When the light is off, the battery reads 14.5 volts charging when i rev the bike, but soon as i switch the lights on it only charges the bike battery 10.5 max.
Thus the battery runs flat.

If there is anything wrong with the coil, would the bike still run smooth. Currently the bike goes fine, no problem starting or no backfiring ect.

Hope you can help......

Sounds like a stator/AC generator fault to me. The stator lives in behind the flywheel.

If a winding is damaged/burnt out, or any of the connections damaged, then the more load you put on the system, i.e. lights, then the less charge that will reach the battery.

Try riding with the lights off and then hitting the "pass" switch. Sometimes this will cause the motor to misfire slightly, or briefly drop a cylinder.

Best thing to do is to pop the flywheel off (use the correct puller, not a hammer!) and remove the stator. Carefully check the windings - maybe even take it to a good local MX dealer to get it checked out.

Andy.
NSR-WORLD.COM

Thanks.

Is there anything else I can try 1st, I do not have the right equipment to remove the flywheel.

I will check the connections on the outside 1st for a try. Hope not I have to go as deep as you suggest.

Sorry Jaco, but if there was somewhere else I thought you could try first, don't you think I would've mentioned it!

If you are lucky, you may find that your local dealer will lend you a puller if you offer to leave them a small deposit. Alternatively, a puller isn't very expensive - in fact, we're looking into selling them through the Site soon!

Andy.
NSR-WORLD.COM

Isn't there a set of readings to test the stator / rotor with a multimeter first?
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Yes, there is. Bike shop gave me details. But I opened the the Stator coil and it was dirty/Oil. My cover was not sealing proper, and a leak from my exhaust into engine ran down into the cover.

I cleaned it last night, will test it tonight and let you know.

Probably Dave, but as Jaco says he's already tried the reg/rec and battery on a different bike, then there ain't much left!

Popping the flywheel and of just leaves 3 allen-head screws (as you know) and a couple of multi-plugs, and usually a quick visual inspection is often enough to see a fault. If not, why not just whip it down to a local dealer and ask them to test it?

I will try to find some test data, but taking the flywheel off and inspecting the stator would be my next step as I don't think I have the information for testing myself.

Alternatively, if there is another NSR to hand (the one the reg/rec/battery was tested on) then I'd be inclined to swap out the stators!! In my opinion, if you must have a fault, and have 1 good working bike and 1 faulty one, it's the ideal position to be in!! :)

Andy.
NSR-WORLD.COM