Topic: cb550F losing spark while i go down the road

[sbkaye]

HELP !!

I'm not an experienced motorcycle mechanic.  My sons and I bought 3 cb450s and a cb550 a couple of years ago and have been doing cafe conversions on them. 

My 550F is giving me problems.

I've checked the fuel delivery.
carbs are clean
intake boots are like new and tight.
fuel is getting through the carbs, and drains from the bowl drain screw as it should.

the problem is intermittent, which is the most difficult for a rookie like me.

here's what usually happens...
I'm riding down the road, doing fine, and then it just goes dark...as long as i keep the engine engaged, it keeps trying to pull but winds down.  if i clutch it, it immediately quits.

sometimes, if i wait a while...stranded by the side of the road...it will restart.

also, there are times when i just can't get it to start at all.

the battery is new.
the wiring is stock.
no fuses are blown.

Please help me.  I know this thing can be a reliable rider.  as it is, it's just an expensive paperweight.

thanks all.

Scott

[Steve_K]

Quick check would be the vent in the gas cap.  When it dies open the gas cap as soon as you safely can.  If the vent is plugged you will hear some air going into the tank. 
It does sound like lack of fuel. 
Anyway I would try that first.
Steve

[kingrabbit]

Don't lose heart.
When you say it dies on the side of the road like that do you mean the electrics die too? As in no lights? Or just that the engine dies?
If it is just the engine then I agree it could be a fuel issue.
Start with the gas cap vent. Sometimes its a little triangular hole and it could be obstructed by polish or other crap.
Another question -when the bike restarts after stopping on the side of the road is there a lot of smoke? Is it flooding?