4,000 RPM Idle When Warm

[Larry]

I need some help guys.  I bought a used 2000 GS500E with 3,200 miles.  It appears to be 100% stock. The bike had sat during 2004 and the dealer cleaned the carbs and adjusted the valves when I got it in Feb 05. For the first 150 miles it ran great (weather was cooler here in PA during March).  After the first warm day in April, the bike continues to start and idle OK at 1,200 RPM, but after 20 minutes of running  the idle jumps up to 4,000 RPM.  Other than the high RPM the engine response seems OK.  When the engine cools down, the idle returns to normal.

I presume I need to look for an air leak that developes after getting warmed up.  Please point me in the right direction.  Thanks.

[davipu]

carb boots

[marc]

get a screwdriver and turn 1/2 turn clockwise the mixture screw.

If it does not work, return the screw to its position.

[shaykai]

My GS used to do this and I just adjusted my Idle screw when it was fully warmed up and this fixed my problem. The only downside is it idles pretty low until its properly warmed up

[scratch]

Use your throttle to keep the rpm's up when you turn the choke off (choke should be turned off after no more than 2 minutes to avoid fouling the plugs and wasting gas, the bike should be ridable, but may still exhibit it's cold-blooded nature).

[gazingwa]

Wow, My gs takes no more than a minute to idle without choke even in 50 degree weather.

[Larry]

I think I am headed towards taking the carbs off and removing the brass cover on the air mix screws.  It sounds like this is the typical "too lean" problem on the GS.  BTW, my choke also works very fast on a cold start (under a minute).

[DerekNC]

It might be a good idea to pull the carb to engine intake boots off and replace the o-rings. The boots on my bike were still in good shape but the o-rings had become completely flattened.

Derek

[Larry]

Thanks for the info.

[vfrocket]

My GS used to do this and I just adjusted my Idle screw when it was fully warmed up and this fixed my problem. The only downside is it idles pretty low until its properly warmed up

Mine does the same thing... If I try to adjust the idle after I first start it up the rmp end up too high once it warms up.

[Larry]

Davipu, you were right.  It was the carb boots.  WD40 found the air leak.  Seems like the shop left the clamps too loose.  Thanks to all for the help.

[GT Eye]

Which way do I turn the idle screw anyways?

My idle is too low and the bike dies unless I apply some choke or throttle.

[The Buddha]

Unscrew the idle screw 1/2 turn ... its not clock wise, its counterclockwise, but its upside down ... so whatever ... its out 1/2 turn.
3 turns out is a starting point for most bikes/carbs ... opening out a bit or in a bit is common.
Cool.
Srinath.

[Kerry]

Which way do I turn the idle screw anyways?

If you're talking about the idle adjustment screw between the carbs (instead of the air/fuel mixture screw on EACH carb) ... think of it as a jar lid, or a regular machine screw (which it is, I guess   ).  Tightening will raise the idle, loosening will lower the idle.

If you sit on the bike and grab the idle adjustment screw with your right thumb and finger(s), PUSHing with your thumb will raise the idle, PULLing with your thumb will lower it.

If you tend to forget such mnemonics, just turn the screw and watch the tachometer needle.  :dunno:

Hope that helps!