Topic: CB650 won't stay running

[gaudry]

First of all, thank you to everyone for your help in the past. I was able to track down the cause of some issues I was having with fuel pouring from my carbs thanks to your help!

My current issue is that the bike won't stay running. I can get it to start up either with starter fluid or if I nurse it and give it some gas, but it always just dies pretty quickly, and dies if I ever give it more than 1/4 throttle.

I suspected the carbs were STILL dirty, so I went ahead and boiled them in simple green, checked the main and idle jets and blew carb cleaner through both of them, but it still acts like the carbs are gummed up. I can't imagine it could get much cleaner, so I'm at a bit of a loss.

I still think something is up with the carbs since it will fire up right away on starter fluid, but it's a real pita otherwise.

Do you guys have any ideas?

[jerry h]

When I had a 650, the starting procedure was to twist the throttle once or twice, then use FULL choke to start.  As the engine starts to warm up, then ease up on the choke slowly, may take several minutes until its up to operating temp.  They are jetted pretty lean from the factory, don't be afraid to use the choke.  When completely warmed up, you won't have to use the choke like on a cold start up.

[gaudry]

Thank you, that has been my experience thus far. I've been using full choke when trying to start it and keep it running, but it still just dies after I get it to start up.  Without the choke, it won't so much as cough

[harisuluv]

Probably clogged idle jets, but that's with very little information provided.

[trueblue]

How long are you keeping the choke on for?  With my 650 I find if I give it 4 good cranks on the throttle, then pull the choke fully on and start it, I then wait till it starts to stutter on the choke before I release it.  This can take a couple of minutes, then and only then will it consistently idle and run right.  They are very extremely cold blooded, but once started I don't have to touch the choke unless it is a cool day, when it may need it after sitting for about 4 hrs.