1979 Yamaha XS400

[stalcry]

So I’m having issues with the battery- I’ve fully rebuilt the entire wiring harness and went by the recommended factory battery, but it didn’t seem to give off a lot of power. I’ve double checked everything and power is in fact getting to it but it doesn’t seem strong enough and it’ll die after a couple hours. I remember when I originally got the bike the owner had a battery on it that was crazy expensive and tiny, but I can’t remember at all which the power was on it.

Thank you!

 

[CaptChrome]

Sounds like a voltage regulator issue if the bike dies after a while. You should put a volt meter across the battery terminals while the bike is running and it should show the DC voltage just over 14 volts. Reving the throttle should produce an increase in voltage, but it should not go higher than 14.7 volts.