Won't start when hot

[Anonymous]

1982 GS1100G. The bike won't start (behaves like the battery is almost drained) after riding for a while. But, after letting the bike cool down it will start with no problem.
I had the starter rebuilt last year and just installed a new battery and neither helped.

Any suggestions as to what could cause this?

 

[kz]

My Honda CBX 1047, 1979 was exactly the same and I tried a lot of things, in the end it was the battery itself, which was bad, and after I replaced the battery the bike started as it should warm and cold.

You wrote you already changed the battery so I don't know, but this was the error on my Honda......

 

[SqDancerLynn1]

next time get a big screwdriver and try jumping the starter relay to see if that helps, you could still have a bad starter, or bad start switch, bad connections. Someone made comment that if the starter housing bolts are to tight it can cause the starter to drag.(Not the mounting bolts)

 

[Anonymous]

My CB 1100 F was doing the exact same thing when I baught it. Found the previous owner had installed a battery one size smaller than it needed.

 

[argonsagas]

First thing I would check for is a bad ground.....expands when hot and the ground becomes poor, but is OK when it cools and contracts. Had the same problem on a brand new Ford years ago. It was under warranty, but mechanics could not find the problem....always worked for them. Pulled off the cables and found a slightly bent washer between the ground cable and the engine block. Threw it away and had no more starting problems.