Topic: cb750 k5 no power help

[dariusk5]

a couple nights ago my bike was riding kinda rough, hesitating and bogging down, and the next day i go to start it and nothing, no lights at turnkey, brake lights dont come on, and i cant kickstart it, battery is charged. if anyone could suggest where i should start looking for a problem it would be greatly appreciated.

[Gordon]

You say the battery is charged, but is it holding a charge?

Check the battery terminal connections, check the ground connection, check the main fuse, and check the wiring connection on the back of the ignition switch. 

[Duke McDukiedook]

Then you'll want to put a voltmeter on the battery terminals and take voltage readings at different RPM numbers in the manual. Look at the manual to see what the voltage readings at different RPM's should be.
 

[dariusk5]

 checked out the battery charge, its good, and the connection at the back of my keyturn looks good( no wires hanging out)ok sorry for being so unknowledgeable, but im not really sure where the main fuse is located, i thought it would be in the headlight, but nothing in there really resembles a fuse, also what is the component that has the positive battery terminal( the first component from the positive battery terminal to the rest of the bike)? thanks for any help

[Duke McDukiedook]

Type of bike, year?

[dariusk5]

1975 sohc cb750

[Gordon]

Type of bike, year?

In the thread title.

[Gordon]

checked out the battery charge, its good, and the connection at the back of my keyturn looks good( no wires hanging out)ok sorry for being so unknowledgeable, but im not really sure where the main fuse is located, i thought it would be in the headlight, but nothing in there really resembles a fuse, also what is the component that has the positive battery terminal( the first component from the positive battery terminal to the rest of the bike)? thanks for any help

On the ignition switch, you're not really looking for loose wires (although that wouldn't be good).  Check the plastic block connector.  I'm not sure where it is on the K5, but it will either be directly on the back of the switch, or several inches down the line on the wiring harness.  The connectors on the back of the switch can work loose or crack and cause a problem.

The main fuse is on the fuse block behind the left side plastic side cover, just under the left side of the seat.  The main fuse should be the 15A one. 

The first item that the positive battery cable goes to is the starter solenoid.  Check that it has a good, tight connection, but don't forget to check that the negative (ground) cable is firmly attached to both the battery and the frame of the bike. 

[dariusk5]

found the main fuse and replaced it, about three minutes of riding later it blew, i rode it home on a 7a fuse with the headlight off,made it home. as for the starter solenoid it has a somewhat substantial amount of rust on the top of it and im looking to replace it soon, im hoping this will fix the problem any more advice would be awesome, thanks everyone.