I just bought a 93 GS500.  It starts and runs perfect and has about 28K miles.  Bike was very well maintained.  I noticed that when opening the throttle (in neutral) very slightly the engine speed jumps right to about 3000 rpm?  Is this normal?  It idles nice and smooth at 1200.  I've tried opening the throttle as slowly as I can but it just goes right to 3000 as soon as the throttle begins to open and when I back it off the slightest amount it returns to 1200.  
Thanks guys

Anyone?

I've got an overspeeding problem with mine I'm trying to get sorted out. If you didn't see my thread you might try checking the throttle and choke cable to make sure they have a slight amount of slack in them. You can also spray WD40 near the carbs while it's running to see if the engine speeds up. If it does you have an air leak. Good luck.

Derek

How does it rev to 4000? And does it come down the same?

How does it rev when you open the throttle the way you would normally open the throttle?

It sounds like something is sticking. Because the bike carburates well. Otherwise, I would say something is lean, like the mix screws.

Does the throttle stick, hang up, or feel notchy?

With the engine off, close your eyes and feel as you twist the throttle. If the cabel is good, you should be able to 'feel' if the butterfly valves 'give'.
Or, maybe even the cable (if it's rusty inside the sheath).

I told the other guy to check his valves.  

Mine did the same thing sometimes.  It warmed up like crap, stalled everytime I stopped, and when I turned it off to get gas and started it up again it would go to like 4-5,000 for several minutes.  It was embarassing!  I started turning it on IN GEAR so I could take off right away so others wouldn't hear it.

Tight valves do weird things.  I'd ALWAYS check them before doing any carb work.  It's easy to check them, very easy.

Hey Joe, did the valve adjustment pretty much cure all the problem? I think I'll check mine to see if they're out of adjustment. A lot of other people are having the overspeeding problem so it would be nice to pinpoint the source of trouble.  Thanks. BTW Popsicle, I know what you mean about being embarassed about the reving engine. I have to get my endorsement put back on my license and can't you just see it now. The examiner instructs me to start the bike. As I do the rpms go to 4000 and my riding test goes to 69.   :lol:

Derek

Quote from: scratchHow does it rev to 4000? And does it come down the same?

How does it rev when you open the throttle the way you would normally open the throttle?

It sounds like something is sticking. Because the bike carburates well. Otherwise, I would say something is lean, like the mix screws.

Does the throttle stick, hang up, or feel notchy?

With the engine off, close your eyes and feel as you twist the throttle. If the cabel is good, you should be able to 'feel' if the butterfly valves 'give'.
Or, maybe even the cable (if it's rusty inside the sheath).

The rest of the rev range is fine.  Just off idle goes straight to 3000.  It idles perfectly at 1200.  Throttle is very smooth and doesn't stick or hang up.