Hi there,

My first post so go easy....

I recently bought a GS500E after having ridden a SpeedFight II 100 for the past 5 years.
The SpeedFight I had from new and was regularly serviced and ran like a dream (well, as much of a dream as a scooter can..).

The GS500E is 10 years old and there have been a couple of minor problems that I've had to fix.  There's one problem left though that has me stumped:

When the engine gets warm (after 10minutes idle or riding) the throttle seems to stick open.  A mechanic said it might be sticky slides so he gave me some stuff to put in the tank.  Hasn't made any difference.

It's a bit embarassing when I'm sitting in traffic and the revs are sitting over 4k!  The only way I can pull them down is to engage the clutch slightly for a second.

The danger is that I can't rely on the engine breaking too much.

Does anyone know what the problem might be??

Thank you!!

Quote from: rikardo..When the engine gets warm (after 10minutes idle or riding) the throttle seems to stick open.  A mechanic said it might be sticky slides so he gave me some stuff to put in the tank.  Hasn't made any difference...

Greetings and welcome to the group! One Euro member posted a problem similar to this not long ago, but I am not sure what the complete resolution was...if any.
Here is one thread that may provide some ideas. As with any thread, try to read the entire thread and possible cross references to get the complete discussion.

To get a huge search return of threads on "slides" put "slides into the search box and run it. You will get this thread and many more. You can use Boolean operators to narrow the run.

How many original miles are on the GS, if you know?

Like one moderator, Roadstergal, says "Carbs are the devil." We do have many members with carb experience though. They will be along shortly.

I had a similar problem long ago, and it in fact was a slide-spring... or so my mechanic says.   :dunno:

Be sure to fiddle with the idle adjustment.  Get her nice and warm and use the idle screw to get the idle dialed in, then use the choke to adjust the fuel mixture when cold.

Might want to lube the throttle cable just to rule it out.

Welcome!  

Thanks guys.  I'll hunt through the threads and see what I come up with.

I thought about lubing the throttle cable but I couldn't understand why that would cause a problem only when the engine is warm??

The other thing is there's very little (if any) freeplay in the throttle so maybe it is more cable related after all.

(looks like I'm actually going to have to get my hands dirty!!!)

Welcome!

And, the carbs are properly seated?

I had the same thing happen on my bike when I first got it. The reason was that the IDLE adjustment screw was screwed in to tight. It worked great when the bike was cold, but once it got warmed up the IDLE would stick at around 4K.
Here's what I did to fix it.
Warm the bike up (ride around for 1/2 hour or until the idle stays up above 4k)

Make sure the choke is 100% off.

Park the bike, turn it off, and turn the idle adjustment screw out(make sure you wear good gloves because the engine will be hot)

Start the bike and rev the engine up above 5K for a few seconds. Let go of the throttle and see if the idle comes down.

If the idle gets stuck before dropping back down to 1300-1500 Keep on turning the idle adjustment screw until the RPM's come down normally. Make sure you only let the screw out enough to get the IDE down to 13-15K. If you turn the screw out to much it will be hard to start the bike when it's not warmed up.

Try this, it worked great for me.

check to make sure the choke is actually coming out when you move the lever on the handlebars.  My old GS had a sticky slide, and I had to reach down to push the choke slide all the way out after pushing the lever.

This is why we say to set the idle when the bike is warm. If you set it while warm, you will only need to use the throttle a little bit to keep the rpm's up to 12-1300 in the morning, or when it's cold.

You either have a lean pilot (designed that way in US bikes ...  :x ) or a sticky choke or throttle cable of course ... a slight stick will pass as un noticeable when cold and be a nightmare when warm.
Cool.
Srinath.

Thanks guys!!

Plenty for me to try out when I get off my but..

I had the same problem.
Turned out to be 3 things.
Choke slide broke, not allowing the choke to shut all the way.

O-rings in the carb ( float o-rings qty 2) allowing gas to seep by, allowing gas to cnstantly feed the intake venturi.

Float needle had a crack in it, keeping the float from closing without leeks.
The needle having a dent where it has been seating for years, is a very common fault.
If your problem is not a cable,
I highly recommend getting a rebuild kit. otherwise you will be chasing small problems for a long time.