Topic: cb500 stalling and starting issue

[vonvendetta]

Video below showing that it will not stay running. I am about a day away from riding it and I have this happen. In the past when putting the bike together it would idle great but now I am having issues with it staying running.
Think this is just a simple carb clean?

I have a shorai battery but use this monster when testing.

[vonvendetta]

Cylinder 3 is cold but getting spark. Fuel?

[Hot500]

Are you using any choke? Is the bike cold? The motor spins up very fast, like there is a lack of compression. Checked the valves lately?

[vonvendetta]

It is cold yes and I was not using the choke. I have not checked the valves.

[Hot500]

The carburettors on these old bikes are a pretty simple affair. They dont like to idle when cold. Use the choke. Turn up the idle screw and let the motor warm up. If you can get it that far you then need to syncronise the carbs so that they are all operating the same.

If no. 3 pot is cold then there is no combustion taking place. Probably a stuck float. Give the float bowl a tap with something to loosen it up.

[dave500]

your not making the correct facial grimaces?how much fuel is in the tank?

[bjbuchanan]

The carburettors on these old bikes are a pretty simple affair. They dont like to idle when cold. Use the choke. Turn up the idle screw and let the motor warm up. If you can get it that far you then need to syncronise the carbs so that they are all operating the same.

If no. 3 pot is cold then there is no combustion taking place. Probably a stuck float. Give the float bowl a tap with something to loosen it up.

Disagree, don't touch the idle screw, leave it where it is and manually warm it up. If a cold motor, choke it to start and remove the choke pretty much after startup. Much more than that and you are just fouling plugs unnecessarily. Try it, you might like it.

I agree with the float tap, its probably hung up. If it sticks, is cold, pisses sometimes, sticks again other times make sure you have no gasket interfering with the float. IDK if that model uses the o-ring type, I'm used to 750's and 400's

[Stev-o]

The carburettors on these old bikes are a pretty simple affair. They dont like to idle when cold. Use the choke. Turn up the idle screw and let the motor warm up. If you can get it that far you then need to syncronise the carbs so that they are all operating the same.

If no. 3 pot is cold then there is no combustion taking place. Probably a stuck float. Give the float bowl a tap with something to loosen it up.

Disagree, don't touch the idle screw, leave it where it is and manually warm it up.

+1...don't play the idle adj game.  Take 2 min to warm it up and then your off. 

Have you done the full 3000 mile tune up?

[dave500]

ive never tried but I doubt mine will start without choke in summer without a long crank and fart around?ill try it tomorrow just for the experience.

[vonvendetta]

I'm about to do the 3k tune again. It sat for about three months not running so I'll do a quick clean to carbs as well.

[dave500]

id go over your ignition fully first?i feel carbs get removed over and again for no reason?if they've been cleaned and good to go that's all they need? unless you get gas from a a third world toilet?

[seanbarney41]

id go over your ignition fully first?i feel carbs get removed over and again for no reason?if they've been cleaned and good to go that's all they need? unless you get gas from a a third world toilet?

that's a good and accurate description of U.S. 10% ethanol gas, Dave.

[vonvendetta]

Turns out one of the float springs was not springy enough. Replaced it with a spare, adjusted the float and changed a loose wire. Boom!

Now to get the signals and lights on to get it on the road this week.