748R regulator/Battery failure ???

[748R_bb155]

Case :

When running the engine without eletrical load. (No lights)
The Batteri voltage is about 13.4 V

When turning on the headlight it goes to 12.6 volts.

Running without headlight again 13.4 volts, using the brake lights
down to 12.6 V.

Running with the rear light disconected and headlight 12.6 Volts.

Al tested on a freshly charge battery (2 years old).

With the eninge stoped, the battery voltage is 12.4 to 12.6 but goes under

11.5 when using any of the lights on the bike.

Any suggestion to the cause of this problem ??

Defective battery ??


EO

[916duc]

Put a voltmeter on the battery and run @ 4K rpm, what voltage reading are you getting?

Check the fuse for the VR in the fuse box next to the frame.

You can check stator output easily by disconnecting the VRR and connecting the voltmeter to the stator leads (CAUTION this is AC current and will zap you). Again at 4k rpm you should get an AC volts reading of 50 +.

If you have AC voltage from the stator and the VR fuse is OK but less that 12.5 volts DC at the battery @ 4k rpm, you've got a VRR problem.

[john S.]

DC voltmeter to battery, should be about 12.5v. Start the motor, if its the same regardless of the rpm, your system is down. My experience is when you blip the throttle you get about a one volt increase.

Another test is start the engine, it should again go to 12.5v and have a jumpy idle. If its stable your vrr is not charging the battery.

Do you have a generator light? If you do has if been on or flickering?