Author Topic: Lumpy Idle and Stalling Issues (Read 4303 times)

MasterM3 · « **on:** April 06, 2006, 03:27:27 AM »

Hey guys,

I let my bandit sit for a little over a week while I was away on spring break. Afterwards, I took it out for a spin and had it stall on me while pulling away from a redlight. At the next light, the bike stalled again. I coughed it up to not riding for a week and being a little too quick on the clutch.

tonight, I took her out for a spin again. Didn't do anything out of the ordinary. Went on the freeway, everything was fine. I exited the freeway to grab a burger and I noticed the idle was very lumpy when sitting at a stop. It would bounce up and down and the headlight would dim as the revs dropped. I sat there and it bounced up and down while I waited for the light to turn green.

It turned green and I had to give the bike quite a bit a gas to keep it from stalling. It would stutter a bit as I started to move, and once I got moving around 2k rpm's, it would run fine. I had to take the freeway back and luckily hit all green lights and the bike ran well all the way up until I hit a red light.

Anyway, once back home I let it sit and just watched the idle jump up and down and the light dim. It wouldn't stall, it would just sit there revving.

I don't know anything about motorcycles really, but a quick search on the forum leads me to believe it could be carb related. The previous owner cleaned the carbs and had them synched not too long ago, which is where I'm a bit stuck. If anyone could give me some advice I would appreciated it. I'm a broke college student and I'm afraid I might have to take it to a shop.

Also, the bike sat outiside during some heavy rain, but it was covered so I' don't think that has anything to do with it.

MasterM3 · « **Reply #1 on:** April 06, 2006, 11:59:05 AM »

some more reading around has affirmed my belief that this is somehow carb related. although i am positive the previous owner cleaned and synched the carbs very recently, im not sure what else this could be.

i bought a slip on exhaust and was looking at jet kits. i would have to take the bike to a shop to get the jet kit installed, so i guess cleaning/synching the carbs could be done while the jet kit was being installed. am i correct?

PitterB4 · « **Reply #2 on:** April 06, 2006, 12:37:51 PM »

I'd check your plugs and all plug wire connections before tearing into the carbs. I'd resynch the carbs after installing the jet kit anyway.

Good luck

magicGoose · « **Reply #3 on:** April 06, 2006, 12:57:00 PM »

Yeah, what Rob said.
Also, a bad reg/rect can cause symptoms like this. The dimming headlight makes me wonder. Check the voltage on the battery according to the service manual procedure.
Lastly, FWIW I would never do something like install a jet kit if my bike wasn't running fine to begin with. It's just going to add another layer of complication to troubleshooting if everything isn't 100% afterwards.
good luck,
Steve

MasterM3 · « **Reply #4 on:** April 06, 2006, 01:10:16 PM »

thanks for the input guys. the thing that has me really confused is all the maitinence the previous owner did. he was quite a competent mechanic, working on bikes his for a good number of years. Here is a list of all the work done about 500 miles ago

> Josh,
> Here's a list of items that were done;
>
> New air filter, just cleaned
> New sparkplugs, less than 500 miles ago
> Replace sparkplug wires and seal with RTV
> Rebuild and synchronize carbs, last year
> Reglue intake manifolds from air box to carbs, 2 years ago
> Reglue vacuum tube from #1 intake manifold, 2 yrs ago
> Replace fuel tank petcock (old one is in box and still good), last year
> Clean out vacuum tube check valve which connects fuel tank to petcock,
> last year
> Lube cables, just did clutch
> Repair choke cable with heat shrink tubing by lever and lube, last summer
> Installed smaller turn signals, 2 yrs ago
> New tires front and rear 2,000 miles ago approx
> New chain and sprockets, 1,000 miles ago, should last 20,000 miles if kept
> lubed and adj
> New brake pads in rear, can't remember about the front one
>
> The bike has a battery tender hook up. So if you purchase a battery
> tender (trickle charger) you can just plug it in to the bike w/o having to
> remove the battery.

I only suggested getting the jet kit because i figured the carbs could be synched again while the kit was being installed. I will check the battery voltage as you suggested

Thief400 · « **Reply #5 on:** April 06, 2006, 02:27:49 PM »

I would check to make sure the choke is coming all the way off. Seeing as the cable was fixed and not replaced would suggest to me that the choke may be sticking on. This affects the idle more than the rest of the rev range. Look on the left side of the bike and push the enrichment bar over and see if it moves. if it does then theres your problem

MasterM3 · « **Reply #6 on:** April 06, 2006, 09:34:25 PM »

Quote from: "PitterB4"

I'd check your plugs and all plug wire connections before tearing into the carbs. I'd resynch the carbs after installing the jet kit anyway.

Good luck

forgive my noob-ness but can you tell me how to check the plugs? and what i should be looking for? the manual doesn't give any directions on how to take out the plugs

MasterM3 · « **Reply #7 on:** April 07, 2006, 04:22:49 AM »

Quote from: "Thief400"

I would check to make sure the choke is coming all the way off. Seeing as the cable was fixed and not replaced would suggest to me that the choke may be sticking on. This affects the idle more than the rest of the rev range. Look on the left side of the bike and push the enrichment bar over and see if it moves. if it does then theres your problem

where can i find the enrichment bar?

PitterB4 · « **Reply #8 on:** April 07, 2006, 09:58:45 AM »

Sonofa... I just typed a book and had a mini board crash and lost it! I'll try to redo it...

Plugs - pull the tank, pull the plug wires (noting where they go), pull the plugs (17mm plug wrench, IIRC). They should be clean and a tannish color. Do some research. There are some good web sites about how to read plugs.

Choke/enrichment - the choke lever on the bar runs a cable that controls a bar that runs along the front of the carb bank. It opens and closes the choke circuit on each carb. If you have a problem with your cable or the movement of the bar on one carb, it may not be allowing the choke to turn all the way "off". Move your choke around while looking at the carbs. You'll see the bar sliding back and forth. Note the direction it moves when you turn the choke "off". When it's all the way off, see if you can push the bar further in that direction. If so, you've got a problem with the cable or somewhere else in the movement of the system.

Also, Goose makes good points. If all that work was done (correctly) on the carbs and plugs/wires, your reg/rec might well be the culprit. Trying to tune the bike with a jet kit will likely be a real headache if you haven't nailed down whatever is currently ailing the bike.

Good luck.

Katamaniac · « **Reply #9 on:** April 07, 2006, 02:57:43 PM »

I would definately get this problem fixed before you put that D&D on. You will definately need to rejet when you alter the exhaust. You don't need any problems stacked on top of the one you already have.

I would tend to lean toward the charging system problem. If you want some help with that issue I would check with The GS Resources. There is a wonderful stator page on there which will get you headed in the right dirrection.

http://www.thegsresources.com/gs_garage.htm

Scroll down to the stator papers and have at it. You can also go into the forum and do a search in the technical info section for questions from other members about R/R and stator problems.

MasterM3 · « **Reply #10 on:** April 07, 2006, 04:41:58 PM »

I took the bike to a local shop. Once i arrived there, i couldn't get the bike to replicate the idle surge. the mechanic suspected it had something to do with the record levels of rainfall. though the bike was covered, he suspected some water got inside the tank. he said the bike should be okay.