Quits at Idle

[sraney]

I've lurked here for several years, but my 2001 Bandit 1200 has run perfectly, so no need to post.  Well, now I'm interested in your thoughts on a sudden occurrence of the "dieing at idle" syndrome.  The bike has just over 3,000 miles, very easy and infrequent use (typically 3,000-4,000 rpm, occasionally up to around 6,000 rpm), and virtually no maintenance other than oil & filter changes thus far.  (I know, pretty shocking--I haven't touched the valves, and I use plain old 10W40 dyno oil!)
     I haven't done any troubleshooting yet, but here's the scenario.   Yesterday the bike starts normally on choke (after maybe two weeks sitting idle), runs & pulls smoothly on partial choke for a couple of miles.  When I close the choke completely, however, the bike dies at the first stop sign.  I don't think too much about it, restart, and pull away.  However, the problem persists even after the bike is fully warm (first time this has happened), and it doesn't seem to respond to the idle adjustment at all--just dies every chance it gets.  I turn around and get it home by "gunning" as required every time I need to stop.  By the time I'm home, it'll reluctantly respond to the idle adjustment knob, and I manage to keep it idling by itself around 1200 rpm.  By that time, I'm hot and have lost interest, so I park it in the garage for another day.  Again, it pulled smoothly from about 2,000 rpm up; no stumbles or hesitation, but died almost immediately at idle.  I'll check the plugs (original) & maybe run a little carb cleaner, but I'm interested in any other thoughts.  Thanks.

[Vee Dub Nut]

could just be gummed up... try running some cleaner through it with fresh fuel..

and put some miles on that thing..  

[Red01]

A 2001 with only 3000 miles? The problem is you don't ride it enough. Seriously.

If you let a bike sit for over a month without starting, gasoline will start to turn to a gummy varnish-like substance and this will clog up the tiny passages in the carbs - unless you're adding in a fuel stabilizer like Sta-Bil, or draining the carbs when the bike sits unused.

Since it still runs OK as long as it doesn't have to idle, you can probably get away with an in-tank fuel system cleaner. Chevron's Techron is what seems to be the most popular, with Seafoam running a close 2nd. Try one of these products for a couple of tanks worth of fuel - and go ride those tanks of fairly quickly

[PeteSC]

Dittos on the Techron, and Stabil.
  Sounds like your not riding the bike much, or regularily.
  I've got two bike, and neither really gets used much.
  I've tried to get into the habit of keeping stabil in both bikes, unless I know I'm riding the thing daily for a while....which actually happens...sometimes
  You may want to change plugs, also, since they seem to go south if you're running 'ancient' gas...and/or attempting to ride with the choke on.

  I try to keep a 5 gallon jug of gas around, pretreated with stabil.
  If I take a bike out for a ride....I'll top it off from the jug when I park it.

[Maniac]

(typically 3,000-4,000 rpm, occasionally up to around 6,000 rpm),

Sounds like you need a thorough carb cleaning and balancing, probally due to bad gas like the others have said.

Your also not revving it enough! Come on man, get the lead out!  

Seriously, these are highly tuned motors designed to have the stink revved out of them. Whats your redline, 11k or 12k? Your only getting half the joy out of the motor! Running her low down runs the risk of 'lugging' the motor, and can lead to excessive carbon buildup. Don't be afraid of 10k RPM, besides sounding scary the motor is built to handle it.

Now, I'm not saying ride it in a manner your uncomfertable with, or excessive speed, just take a moment to think if you -really- need to upshift to the next gear the next time you ride. I used to do the same thing, once I learned not to fear the revs things started to get a lot more interesting.  


Good luck getting things straightened out!

[Red01]

Actually, Maniac, the B12 reds at 11K, but you're wasting your time taking it much past 9K, as they're not making power past that. The 1200 isn't the screamer the 400 & 600 are (unless you start changing more than just jetting & exhaust). They're pretty fat with torque from ~2500 to 9000 though.

[Maniac]

Actually, Maniac, the B12 reds at 11K, but you're wasting your time taking it much past 9K, as they're not making power past that. The 1200 isn't the screamer the 400 & 600 are (unless you start changing more than just jetting & exhaust). They're pretty fat with torque from ~2500 to 9000 though.

Ahhh, my bad.  

[sraney]

Folks, thanks for your responses.  While I've been using fuel stabilizer in the winter when I "pickle" the machine, I think I'll adopt the idea of using the stabilizer year-round, since I ride the Bandit too infrequently (one in a stable of four motorcycles).  Also, the "rev the crap out of it" folks will be amused at my experience last night.  I put four ounces of carb cleaner in the tank and rode for about 30 minutes using only first and second gears.  (I discovered that it'll hit 100 mph indicated in second with plenty of room to redline, by the way.)  I kept it mostly around 7-8,000 during the ride.  The idle adjustment that produced a lumpy 1,200 rpm at the start of the ride produced a robust 3,000 rpm "idle" at the end of the ride.  I'm also going to toss in a new set of plugs just to atone for my inattention to my neglected Bandito.  Thanks again for the responses.