Bandit cutting out under throttle.

[Navy_p503]

I thought I'd tap into the brain trust here because I'm fresh out of ideas.
I was riding my 2000 Bandit 600 to school this morning and it started sputtering on me when I turned the throttle. I had just started it, so I turn the choke off. Still sputters. I turn the tank to reserve, it sputters for another thirty feet then just cuts out. It starts right back up and idles fine but as soon as I tried to give it any throttle it cuts out again.
I've checked fuel level (at least above the reserve intake), vacuum lines (all connected and not clogged) Fuel lines (connected and not kinked) and have tried running with all combinations of choke and fuel valve. It will idle fine with the choke on or off, with a very small amount of throttle it might raise the RPM by 1k but after that it cuts out. Tomorrow I'm going to switch the vacuum pickup that the fuel petcock line comes from, empty the tank and pull the petcock out and clean it and check the plugs.
If anyone has had this problem or has any other advice I'd love to hear it. I'm not really sure whats going on so I"m just gonna check all the stuff in the combustion system.
Thanks

[Easy Rider]

Originally Posted by Navy_p503

Tomorrow I'm going to switch the vacuum pickup that the fuel petcock line comes from, empty the tank and pull the petcock out and clean it and check the plugs.

Good start. Be sure to drain the float bowls too. Could be water in the bottom of the tank/bowls.

Might be better to check the vacuum; switching things can sometimes introduce new problems.

If all of that doesn't produce any signigicant improvement, it's time for a healthy dose of carb cleaner.

Long shot wild guess: No ignition timing advance ????

[Clint]

I wondered about timing, too. It seems that a clogged jet would create rough running, but not cutout like you describe.

[Navy_p503]

I haven't messed with the timing at all, I'll have to look at the book and figure out how to check though. Never messed with it on a bike yet. I'm gonna try everything else first, because I really don't want to pull the carbs again, such a PITA. I'm headed over to work on it in about 15min. so I'll update later today. Thanks for the suggestions!

[Easy Rider]

Originally Posted by Navy_p503

I haven't messed with the timing at all, I'll have to look at the book and figure out how to check though.

I knew I shouldn't have mentioned it.

It's not the basic timing but the ADVANCE that might not be working.
An engine will idle fine at the basic timing setting but will not come up off idle much and will seem like it has NO power if the timing doesn't advance as the rpm's go up.

Highly unlikely that is the cause. Like you said, last resort.

[Navy_p503]

Turns out I have a completely transistorized ignition. The only mechanical part is the signal generator. All checked out fine. After about seven hours of work, long story short is the pilot jets were completely clogged. My initial cleaning of the carbs didn't get all the gunk out. My gas tank also had a lot of particulate in it, rust mostly. So I emptied it and put fresh gas in with some Gumout fuel treatment to hopefully clean out anything I missed in the carbs. It's running pretty good so far, I'm planning on riding it around for a while tomorrow to work some of the fuel treatment through the carbs. Thanks to everyone who put up some suggestions!

[Aussie Steve]

I had a similar thing on my B12.... wouldn't run up the rpms then the #four carb started spewing fuel...turned out to be a faulty float valve tip...I know this because I did a temp repair by bending the float tab up to apply more pressure to the valve. Still running it too! temparary has different meanings to some doesn't it!.....course I just jinxed that havn't I?

[Clint]

Glad you got it sorted. Your time's cheap, right?

[Blade]

Also check the throttle slides to make sure they are not sticking.

[metaljoe0]

my bike had been acting similarly for quite some time. when i installed a jet kit, i found that my mixture screws were adjusted from the factory very differently. i adjusted them all the same. that along with the jet kit has left it running much more smoothly with no off idle hesitation any more at all. do you have a copy of the factory shop manual? i have one i could email if you would like. good luck.