1981 cb750c - First time bike build

[kos1113]

The bike wasn't in one piece when I got it but was told it ran fine before it was disassembled.

Question: Finally got the bike put together enough to fire it up for the first time. Ordered a replacement ignition from amazon and turned the key, put kill switch on run, and start...it acted like it wanted to fire so I was like cool. Now all I have to do is run some fuel. Then ran some fuel into the carbs with hose and funnel (tank liner was rusted) turned the key and it wanted to turn over but nothing.

All of a sudden without any popping or indication that something was loose, the start button stops working!! So being the bright guy that didn't do this before all of this started hooking up the headlight and gauges to see if there was power when i turn the ignition on. NOTHING! So my first thought was maybe a bad connection to the battery or bad battery. So we tried to jump it from the starter and it acted like it wanted to turn over! So i dont think its the battery..either a bad ground somewhere, new igntion switch went bad, or bad start button on killswitch.
IDEAS????

 

[Sonreir]

You check fuses yet?

 

[DohcBikes]

^Follow this guy to the electrical promise land

 

[kos1113]

Yeah check the main fuse and the fuses at the igntion. Any that I dont know about?

 

[Sonreir]

Time to bust out the multimeter.

Remove the ignition switch and check for voltage on the red wire, in the plug on the harness side. You should get around 12.5V.

Next, with the ignition switch still removed and in the in position, measure resistance between the red and black wires. You should get a low reading, very close to zero.

How do those check out?