Losing electrical power after 30 seconds running

[Scudster]

Been fixing a shorted out brake light cable and discovered this strange electrical issue afterwards.
The bike starts fine and ticks over fine, lights all working etc., but after 30 seconds or 1 minute of running with or without revving the lights flicker and go dim all of a sudden and then completely off. The bike runs poorly for a few more seconds and then dies.
My initial thought was a broken wire someplace or bad connection but now I dont think it is. I've also noticed the rec/reg gets quite hot (barely touchable for a few seconds)even though it wouldn't have been running very long.
After reading the some other posts with electrical issues, my symptoms aren't quite the same as others but they do hint at similar possible causes.
I have measured the voltage coming from the rec/reg and it's 11.5 - 12.5V even when the lights dim which I presume is a little low but I thought should still be able to keep the bike running.
Would I be right to assume the rec/reg is goosed or worse the ecu? Or the capacitor is faulty?
Why would it run perfectly for up to a minute then suddenly power drops?

[fallenmikethebike]

Your hunch is probably correct, and a duff reg/rec will eventually take out the PGM as well.
Mike

[Scudster]

Cheers Mike.
Electrexworld, here I come....again!
Fingers crossed the PGM is ok.

[knackeredMk1]

It could also be the generator breaking down when it gets hot. Start with the reg/rec.............

[Scudster]

It could also be the generator breaking down when it gets hot. Start with the reg/rec.............

Cheers Knackered.
Is it any harm starting and running the bike with the 12v power disconnected at the plug under the tank and a battery connected in its place to confirm the rec/reg or stator issue?

[fallenmikethebike]

It could also be the generator breaking down when it gets hot. Start with the reg/rec.............

I agree possible, but from personal experience the engine is generally hotter, hot enough to breakdown the insulation material between the coils, but worth checking that voltage is reaching the reg/rec from the 3 phase supply when the engine has stopped.

[Scudster]

FIXED
Replaced rec/reg and running sweet now. Thanks for the help lads.
The replacement I got from Electrexworld is great but not a direct replacement although it's what they supply for the CRM. The 12v out feed cables were half the length they needed to be and the AC input had the wrong type plug and was far too long. Not impossible to remedy but took a bit of cutting and soldering to fix. Another problem was the unit itself was physically bigger. I had to turn the unit around so the cables exited towards the rear and then cut off 3 fins because when the rear suspension was compressed it was hitting it. Also the rear wheel splash guard had to be spaced about 15mm to clear the cables.

[fallenmikethebike]

Excellent news . As others have commented, space is limited for alternative locations to mount the unit, your fix sounds fine though.
Mike

[gregorious77]

I fitted mine on the front of the bike where the horn goes.
http://i71.photobucket.com/albums/i147/ ... 164200.jpg
I recon getting covered in mud all the time is bad news.

[Scudster]

I fitted mine on the front of the bike where the horn goes.
http://i71.photobucket.com/albums/i147/ ... 164200.jpg
I recon getting covered in mud all the time is bad news.

That option did cross my mind but I'm stubborn so it was going in the original location whether it liked it or not!