Idle jump + breakdown on highway

[schaefere]

I have a 97 GS500e. Last time I rode it I let it warm up and was idling ok at about the right rpms. After warming up it jumped up to over 3k, so I adjusted the idle screw to get it back down, but then the next time I came to a stop it died, so I put the idle adjustment back where it was, and figured the rpm jump was caused by something else. As I kept riding, it would idle really high again at stops. After driving down the highway for 10-15 minutes it started stuttering and losing power and it died when I pulled over. It wouldn't start right away, but eventually did after 15mins or so. It idled fine for a while, then jumped up again when I mounted the bike. At this point I figured it was flooding? Anyway, I limped it home with it dying a few more times and having to wait to start it.

I've checked the throttle cable and have no issues there.
I'm thinking there is some junk in the carb that is allowing too much fuel in at idle, and eventually causing it to flood when going down the road. But when driving, if it was getting too much fuel wouldn't it haul ass until it started to flood?

Thanks for your help guys.

**EDIT
Last winter I stored the bike in my father's garage and he ended up taking it into a shop for me. They did some work on the carbs and I was back in business.
I've been riding it around a bit since I got it back in March, but not a whole lot of highway riding and everything seemed great.
Yesterday after about 15-20 minutes of sustained 80mph on highway the bike stuttered once then I lost all engine power. Absolutely no throttle response. Pulled over and it died as soon as I stopped and wouldn't start up again.
I don't have the resources to keep taking it to a shop, nor do I have a truck.
The bike only seems to have issues after a while on the highway, so its hard for me to test it without leaving myself SOL. Thinking about selling because it keeps leaving my in very unsafe situations.

[Big Rich]

Probably not flooding.....

I want to say intake leak around the carb boots. The high idle is a dead give away.

[schaefere]

Thanks, I'll look into that. But I don't understand how an intake leak would cause it to break down then not start for a while. Then again, I'm no expert.

[Soloratov]

A bad intake leak will, for a lack of better terms, dry out the carbs. I had this issue. The bike is essentially running so lean the fuel mix can't keep up with the air mix, so really you are doing the exact opposite of flooding it. You are blowing out the flame. It takes a minute after it shuts off for the fuel to get back into the carbs at the right amount to start up properly. Start the bike, and spray the intake boots with carb cleaner/WD-40. Idle change=leak.

[schaefere]

Update time. I got the idle problems fixed. The bike will idle just fine, had it running for 15-20 minutes while messing with things. Can turn the bars without idle changing.
I tried spraying some carb cleaner on the intake boots, no idle change. Air filter is fine.
I took it around my apt complex and it seemed fine so I went out on the road, for about 1/2 mile until it broke down again. Acceleration was really jerky with power cutting in and out, then I just lost all power and it died when I pulled the clutch. Couldn't get it to start back up even after waiting for 15 minutes or so. BTW battery is fine.
I'm trying to avoid having to take the tank off and get the carbs out because my apartment management doesn't want people working on vehicles here.

As always, I appreciate the help.

[adidasguy]

Do you have gas? (It may look like a lot but the view in the gas cap is deceiving)
Did you try running on reserve?
Is the gas tank vent clogged so no air gets into the tank to let gas out? (try running with gas cap open)

[schaefere]

I have gas, at least a 1/2 tank. I'll try opening the top and see what happens. But it did idle for quite a while. Also, the first time it broke down I checked for gas and I don't recall air rushing in when I opened the cap.

[adidasguy]

Just trying to rule out the obvious. One guy came to the bike cave with fuel problems. after tearing apart the petcock, replacing it and other stuff....

....well.....


......when I helped put the gas tank back on I asked if he knew his fuel problems were because the tank was empty....

We always get good chuckles from the antics at the Bike Cave - we all do less-than-intellegent things and all get a good laugh.

[demonsavatar]

Kinda sounds like fuel starvation to me.  Check your fuel lines and your petcock to confirm there's nothing blocking fuel flow.  When I got my GS500 there was some blockage in my frame petcock, had me confused for a couple days.

I think some people also mentioned something about the gas tank relief sometimes getting clogged so negative pressure builds up in your gas tank?

[The Buddha]

Update time. I got the idle problems fixed. The bike will idle just fine, had it running for 15-20 minutes while messing with things. Can turn the bars without idle changing.
I tried spraying some carb cleaner on the intake boots, no idle change. Air filter is fine.
I took it around my apt complex and it seemed fine so I went out on the road, for about 1/2 mile until it broke down again. Acceleration was really jerky with power cutting in and out, then I just lost all power and it died when I pulled the clutch. Couldn't get it to start back up even after waiting for 15 minutes or so. BTW battery is fine.
I'm trying to avoid having to take the tank off and get the carbs out because my apartment management doesn't want people working on vehicles here.

As always, I appreciate the help.

Other than the obvious - carb - the not running when hot especially on 1 cyl, can be a crank trigger going bad. Right side under the round cover. Easier than the carbs, its dry and external ... but you have to determine the exact reason ... not arbitrarily change parts ...
Cool.
Buddha.

[schaefere]

Bump, updated new situation in my op

Sent from my HTC One using Tapatalk

[radodrill]

how is the carb vent tube router?  one should be routed over the air box to the battery box.  from what I've read is this tube ends in an unsheltered area you can get fuel starvation issues at higher speed.