newbie hoping for a little help w/ my 92- idle/carb problem?

[redpony_02]

I'm a newbie in about every way it counts around here, but I've got myself a 1992 Bandit 400, and I love it.  Unfortunately, it has a little trouble running- and I was hoping someone with a little more experience could point me in the right direction.

Basically, the engine tends to run pretty erratically, regardless of how long it has been running.  In neutral, it tends to idle correctly for a few moments but then falls very low and stalls out.  Revving the engine tends to either pick the idle back up to where it's supposed to be and make it run smoothly for a little while, or, more frequently, causes it to drop down very low and stall out.  If I keep giving it gas, I can usually keep the bike from stalling out, but the engine seems to be running roughly at a low RPM (could it be that some cylinders are not firing when its doing this?).  Does this sound familiar?

Couple other questions- what's the standard idle RPM on this bike?  Any good guides for general motorcycle repair that would be good for a beginner to start with?

[Herr Tod]

You can adjust the idle RPM with the adjustment screw on the left beneath the carbs. Turn it to the right until the engine keeps running without having to use the throttle. Then turn the engine off, let the exhaust pipes cool down and start the engine again. Check that each cylinder's exhaust pipe gets hot. If one does not get hot then that cylinder is not running. Standard RPM should be 1300 - 1400.

[Maniac]

Standard idle RPM on the GSF400N ('92 model) is 1300RPM +/- 100RPM according to my manual

It sounds like your dealing with dirty/out of adjustment carbs. I can't say this for sure, though. First things first, pick yourself up a set of spark plugs and try those. Should be NGK CR8EK or equivilant (beware, the CR8E is a -short- plug, it's not as long as the EK and won't work well)

[PitterB4]

Should be NGK CR8EK or equivilant (beware, the CR8E is a -short- plug, it's not as long as the EK and won't work well)

Huh?  I run nothing but the regular E's (per Jay's suggestion).  The only dif is single vs. dual prong (and a couple bucks a piece).

[PitterB4]

BTW - redpony!

Checking the pipes is a good trick although if it comes and goes, the pipes all may still get warm.  I always have a spray bottle of water to check.  I'd guess carb synch.  Although, if it is irregular, it almost sounds like it could be an ignition problem.  Maybe loose plug wires?  The connections to the caps are notorious.  While you're changing or at least checking your plugs, tug on the caps and see if they come off the wires easily.  If they do, cut 1/2 inch or so off the wire and screw the cap back on.  

Good luck!

[Maniac]

Huh?  I run nothing but the regular E's (per Jay's suggestion).  The only dif is single vs. dual prong (and a couple bucks a piece).

Eh, huh? Hmm, must be thinking of a different one then. Maybe the 8E. I remember mine originally had the wrong ones in it, they were shorter than stock. I thought they were CR8Es, but maybe I'm wrong.

[Vidrazor]

It's your carbs, and possibly your tank as well. I've recently had the same problems with my B4 and dirty carbs were the cause, as well as a pile of junk that was removed from the tank. Not sure why the stuff was in the tank, but unless you feel mechanically proficient at it, have a reliable shop clean out your carbs, tank, and maybe even replace the fuel lines. Definitely have an in-line fuel filter put on the bike.

[scout1248]

also see if ur petcock has a smooth flow through the vacum hole. i have the same problem on mine and i should be gettting my new petcock tomm and ill see what happends. also pull the carbs and clean them