Project: 1985 GS550ES

I'm still trying to think my way through it, but it seems strange to me that you can increase your idle by putting the choke back on when warm. It seems like putting the choke back on should just make it to rich. That's how it is on my 550. I would think this could only increase your idle when there's extra air availabe to mix with the added gas from choking. Are you sure your needles are set in the slides properly, and that your slides are seating correctly, and that all of the passages to your diaphrams are clean? I know you've mentioned that you didn't dip these carbs...I'm wondering if the vaccuum balance on top and below your diaphrams is somehow messing up with the added heat and pulling your slides up in the process. Just a guess though. And a kind of crappy one at that.

Can anyone else speculate on this issue?

Pulled the choke lines and checked their function. All seems well. Suggestions as to what the next step should be?

It really doesn't seem to be the boots. I've got WD-40 all over the boots and there's been zero effect on the high idle.

FYI, I've had instances where my chokes were not threaded in completely, and this let a little air in through the choke passage. Why they decided to make those threads out of plastic, I'll never guess. Check there while you're at it.

Good luck.

Today's plan

Hunt down an air leak. Everything I've found in my searches for this problem (high idle after warm-up) seems to point to some kind of air leak. Several folks had told me during the carb cleaning that I should replace the boots no matter how good they seemed to be to ensure that I avoided this issue. Well, I still think the boots are in excellent shape, but I have to take some time an do some serious testing to be sure.

If I can't find an air leak are there any other possiblities or will that mean I just haven't found the air leak yet? Thanks for your assistance!

I don't honestly know...I just know that adjusting my valves made the bike perform better overall. It seems that bad valve adjustment can cause all kinds of strange problems...just read uncle mike's long thread about his idle problem...

Its definately a variable I would eliminate if it were me...its relatively easy to do.

I meant could valves "out of spec" cause a high idle after warm up?

Haven't touched the valves yet. I was planning on checking them after I got permanent tags. Could valve specs cause the high idle after warm up?

Don't have much to add, only that my 550 seems to have a limit to how high the pilot screws will alter the idel. It may differ, as you well know, between our bikes since mines not in as good a shape and jetted/breathed differently. The pilot air circuit MAY be able to get enough fuel in their to increase the throttle that much, but it seems unlikely. Seems like she would run way too rich when cold if this were the case. I know its low mileage, but how is your valve adjustment?

Fast/High Idle after warm-up.

Well, at the moment I'm trying to get my bike through state inspection, but I've run into a bit of an issue with the idle. Bike starts up first time every time \\/(under full choke when cold, of course). Runs a touch rough at idle and "take off", but once the RPMs hit the 3000+ range (redlines over 10000) it loves to run and sounds and feels great! The problem is that once it's warmed up it likes to idle at about 3000 and the warmer it gets, the higher it wants to idle, up to almost 5000. Not sure if this will keep it from passing safety inspection, but I need to deal with it either way because of cooling issues (5000 RPMs while sitting = nothing good!).

Here's are my thoughts on the issue:

1) Pilot screws (idle air/fuel mix) may need adjustment. Unfortunately, two of four are frozen and were stripped by the PO. Suggestions?
2) Choke seems to be functioning properly, as I can further increase idle by applying choke after warm up.
3) Air leak seems unlikely as I've sprayed intake boot seams with WD-40 to momentarily plug any leaks that may exist. No effect.
4) I've adjusted the throttle cable and it seems to move freely and have enough slack to allow full return. I've also lubed it liberaly. Seems an unlikely culprit since idle is ALWAYS fine when cold and only runs high when warmed-up or hot.
5) Throttle slides, while ever so slightly scratched, do not seem to have excessive wear (besides, bike has less than 4000 miles on it).

Ideas, suggestions, thoughts, tips, helpful hints? I'll take 'em all! Thanks!

Woo very nice sir... now get some new rubbers on her and ride the heck out of her...

Temporary Tags are On!

Haven't been out here much in the last week, but on 6/8/07 I finally got temp tags on the bike and took the first ride around more than the block! Since then I've put about 30 miles on the GS. This bike loves to run!

With two frozen and stripped pilot screws I've still got a challenge with the carburetion at idle, but I'm in the process of moving so my wrench time is super low right now and I need to have the bike mobile for the cross town move when it happens. Next upgrade will be to new tires.

Next step is to get it through Maryland State Inspection, which I expect to get done sometime next week.

PS: I have cleaned up the plastics a bit and I'll be posting "outdoor" (as in non-garage) pics as soon as I can remember to think about pics in the midst of enjoying my daily rides!

If you want sticky I'd go with the following:

Metzeler Lasertec (most expensive of the bunch, but I love em)
Pirelli Sport Demon (cheaper, but a favorite here on this forum)
Dunlop XXXX - Someone will have to add which Dunlop is stickies, I don't know.

~Adam

Thanks for the tire info. I think I'll be leaning heavily to th sticky side with tires. I want to have the best traction, even if tire life is shorter. Besides, it's not really the tires life that I'm trying to extend.

Anything larger than a 100 front tire makes the bike turn in ridiculously slow. I pulled the 110 tire off my 1100 immediately after I purchased it and went to a 100 size. The handling immediately improved, hands down.

~Adam