1978 750B

I have a 750B that's not charging. The alternator is putting out 3.5, the battery is putting out 13 until throttled, then drop to 10. the voltage regulator is staying at 11 without change. Any ideas. Also, does anyone know what the cylinder type thing is that one of the wired from the regulator goes to. There is also the positive terminal going to it....help

Not being condescending, but the alternator is putting out 3.5 what? :laugh:

Generally the voltage output form an alternator/stator is measured in AC Volts, and should produce more than 50VAC on any combination of its output wires, after approx. 4000rpm.

Is the battery new? If its more than a couple seasons old, it should be thoroughly tested to determine actual capacity, or replaced.

Charging system checks a confirmed at battery measurement.
Should be 12.6 VDC OFF (having sat overnight).
Around 13 VDC Idling.
14.5 VDC when revving past approx. 4000rpm.

The wired cylinder thing is probly your rectifier.

Best of luk.

The 78 750B has a combined reg/rec, and the round cylinder thing is the starter solenoid.

Other than that, TeK9iNe pretty much covered it.

Check the reg/rec ground, if it's not grounded it won't work.

steell wrote:

The 78 750B has a combined reg/rec, and the round cylinder thing is the starter solenoid.

Other than that, TeK9iNe pretty much covered it.

Check the reg/rec ground, if it's not grounded it won't work.

:laugh: :laugh: Yep, that'd be right.

it turns out the genius I bought it from had the ground wire going to the positive battery terminal....thank you

Good you found the problem. Have you confirmed the charging figures as per the service manual?
Or are you just out enjoying the ride on a old Kaw?

Every Japanese motorcycle I've owned had a Negative ground. Some of the British bikes had Positive ground just like some of their cars. It makes troubleshooting real "Interesting".

I would enjoy riding it but the carb is all messed up. The main jet is soldered in. I need to find another float bowl. any ideas...