Topic: 76 cb550 driving me crazy!!!

[cafe-ray]

This bike runs great one way. I ride her for about 20-30 miles to work and she runs great no problems. The bike sits for a few hours and on the way home she'll run great and then just die. Completly loses power and 86's. Generaly i can fire her back up and ride for a while until it dies again. I can't figure out what the problem is. Ive rejeted the carbs, cleaned the tank, and put on new coils and plugs. Any one have any other ideas.

[Johnie]

When she starts to die crack the gas cap and see if there is any difference.  Maybe the vent???  I have heard of the amount of fuel in the tank could affect the vent too.  Some guys say if they keep it above 1/2 to 3/4 full it never dies. 

[Gordon]

How's the battery?  And when you say "completely loses power", do you mean electrical or engine power?

[cafe-ray]

It seems to be engine power because all the lights stay on.

[Gordon]

There's all kinds of things that could cause your problem, so you're going to have to start narrowing it down.  When it dies, is it really sudden, or does the engine start to sputter and slowly lose power and die? 

[cafe-ray]

Thanks for taking the time to help me, toda was the 3rd time I've had to walk home. It seems like it dies when I slow down. I dont know if it happens when I pull the clutch or not. There is no warning of it dieing, no sputters or sounds, it just loses power. sometime its slow but most of the time its like hitting the kill switch.

[Gordon]

Nothing's really jumping out at me here.   I was thinking fuel delivery problem, but if it dies suddenly without sputtering (like it does when you run out of gas), then pretty much the only other thing it could be is electrical/ignition-related. 

Check the main fuse and it's connecting clips.  Make sure they're clean and making a good connection and replace the fuse with a new one.  And check all the wiring connections relating to the ignition. 

Do you have the stock breaker points style ignition or a points-less system? 

When the bike dies, will it still crank over easily with the electric starter but just not start, or does it turn over slowly? 

[cafe-ray]

I replaced the whole fuse box. The bike has the stock points and unfortunatly the starter button was missing from the controls, its just an empty hole. I have to kick it, which usally she'll start up on the first kick. I also noticed that the plug wires were hot when I pulled them to check for spark, which also gave me a nasty shock when touched them, kinda like a static shock. I was thinking it might be the charging system. I have the head light running directly off the battery (the headlight controls dont work on the bars). But even with the direct draw it shouldn't be using any more power than usual.

[Gordon]

When the bike dies but the lights are still on, are the lights dim or are they nice and bright like you'd expect them to be?

[cafe-ray]

They are a little dimmer.