81 SX400H

[Tomaximus]

Is the headlight supposed to get brighter when the engine revs?

 

[bakeLit]

A more or less normal symptom of the bike starting to charge at about 2000-3000 rpm. Annoying, but pretty much normal.

 

[xschris]

Check the volts at the battery while it's running. You should have 14.5 at 5k rpm's and about 12.7 or so at idle.

 

[Tomaximus]

Check the volts at the battery while it's running. You should have 14.5 at 5k rpm's and about 12.7 or so at idle.

I've got 12.8 at idle and 14.9 at 5000rpm.

 

[BBS360]

So your charging system is doing well.
It's just how these bikes work.
Going to an LED or HID headlight would give more light for less wattage consumed, and probably have a more consistent brightness through the RPM range.

 

[Tomaximus]

Thanks guys!