Topic: No electrical power to 1976 CB550

[CapeCafe]

It's been a while since I posted and I've developed a problem with my 1976 CB550 that I can't seem to determine the source.  I went out to the shed and fired her up this weekend.  I installed a fully charged battery and it took about 15 kicks and she fired up and ran a bit rough for about 4 - 5 minutes then she seemed to clear her throat and ran and idled smooth at 1250 rpm.  I turned her off and started her a couple times after she warmed up and she started first kick each time.

I went back out the next day to start her again and there was no power, period.  I pulled the battery and it had a full charge and all the fuses look good.  The bike has a basically stock wiring harness with all the connectors replaced during my rebuild five years ago.  I adapted the stock harness to relocate the electronics and battery under the seat but retained all the original stock features of the bike.  The electric start is not working due to a cracked "start" button, but this has been the case the last three summers and never caused any issues; once ridden regularly again she starts on the first or second kick.

Anyone have any thoughts on where I shoot start my trouble shooting since the battery tests strong, all the wires visibly inspect clean and the fuses look new?

Thanks!

[TwoTired]

If you have an F model, check the plug at the back of the Keyswitch.

[Flyin900]

Start checking the 12V sources to see where you have voltage. I have seen fuses that look good and defective inside the silver metal cap area. The ignition switch would be a good point to test if you have no power and the main power fuse for the bike.

If those show voltage start working outward, although if everything is dead then the main fuse or ignition switch seem like likely suspects. Check your ground off the battery too and the main positive wire to the solenoid.