stalls at idle

[niko]

finally got licensed insured plated and all of that this weekend, and got out on the road after work today for a ride around the neighborhood, bike is an 85 gs550L that i got at the end of last summer not running, played with over the winter and got up and running this spring. needless to say things didn't go great but they could have been worse, after around 5 miles or so once the bike was good and hot it is stalling as i come up to stop signs, when i left the house idle is at around 1000 to 1200 but once it is really good and hot it seems to drop to around 800 and want to stall. good news is that if i keep the revs up to around 1500 with the throttle it will stay running, so i was able to get home, but obviously somethin aint right. over the winter i cleaned the carbs, and replaced the igniter in order to get it running as it is now, also sealed the intake, although maybe i missed something? also totally unrelated but cornering at speed felt kind of loose wobbly, maybe the road i was on was a bit gravelly or something, but it just didn't feel quite right, i wish i had a better explanation... anyway, any thoughts?

thanks

[BassCliff]

First thought

Hi Mr. niko,

Have you had a chance to replace the intake boots and O-rings? Seal the airbox with a new air filter? This could be a lean condition due to air leaks in the intake system. Did you over-oil your air filter? Keep us informed.

Thank you for your indulgence,

BassCliff

P.S. Click the link in my sig, go to my website, and see if there is anything there you can use.

[basic]

i have the exact opposite problem, after riding around for a few miles and getting the bike nice and warm, it idles faster. i have checked the plugs and they look nice and tan, not burnt looking. haven't done a plug chop though. not a big deal, i just dial down the idle speed a bit and keep on riding.

[niko]

i tried just upping idle speed with the thumb screw and that didn't have much affect. i have not actually replaced all the rubber as they are pricey, what i did was seal them all with orange hi-temp gasket sealer and replace the air filter, will try the wd-40 test tomorrow and see if i can find any air leaks that way.

[Andrew Stano]

Forget the hi-temp gasket goo as it is not compatible with fuel of any sort.If you go to that much trouble of pulling everything down just replace the "O" rings with proper viton not automotive ones as they will break down and after you wrestle the screws out of the cylender head replace them with allen key head SS bolts.This whole kit Orings and bolts costs a whopping $9.50,I just did mine. Contact robertbarr2@sbcglobal.net and he will hook you up !!! Hope this helps Andrew

[TheCafeKid]

Orrrrr you can just hop on his website at www.cycleorings.com It will pretty much point out to you exactly what you need.

[niko]

ok, ill order the o rings, but what about all the other connections, i.e the rubber boot over the carbs on each side, if there is a leak there the same symptoms right? also does anyone know where the mixture screw is on these carbs, they are different from most of the bikes i see on the forum, there are only 2 carbs with double throats, i think they are mikuni bs32 or something like that, i will look when i get home tonight. if i'm thinking about it right i'm trying to figure out what is causing a lean condition at full operating temp but not at cooler temps, so it has to be something activated by the heat of the engine, like the rubber boots heating up and letting in air. does this make sense?

[niko]

i got it!!! it was a loose intake boot on the airbox, runs like a dream...almost

[BassCliff]

i got it!!! it was a loose intake boot on the airbox, runs like a dream...almost

Good sleuthing! Glad it's running better. There is a thread dedicated to carb specs at the top of the tech section. I'm pretty sure your carbs will be in there somewhere. There is also a 550 manual on my website that you are welcome to.

Thank you for your indulgence,

BassCliff