Issues with GS500 (2008): Stalling and Sudden Acceleration When Engine is Hot

[edes]

Hey everyone, I'm a new rider and I'm having some issues with my GS500. Recently, after riding for about 25 minutes, the engine stalls when I'm at a stop, but only when it's very warm (after around 25 mins of riding like I said). After inspecting it, I noticed that my oil level was almost 2 liters low (out of 3:/ ), so I topped it up. I know I should be checking the oil level myself every time I ride, but as a new rider, I hadn't been doing that. What's concerning is that I never saw the oil warning light come on, so I have no idea how long the bike was running with such low oil levels (the last oil change was about 3 months ago when I got the bike).

Initially, I thought the issue was due to the idle screw, so I adjusted it. Today, I took the bike out for a ride, and everything seemed fine until the engine got warm again. On my way back home (after riding for about 20-25 minutes), the bike suddenly seemed to have instantly accelerated on its own (in less than a second), which was pretty scary. I pulled over, and then the engine stalled, and I couldn't get it to start for about 30 seconds. I then managed to get it started and since I was just a short distance from my house (literally 2 streets), I decided to bring it home. But after about 30 seconds the engine stalled again while riding this time, and I was too scared to turn it back on.

The weird thing is that when the bike is cold it seems to turn on and work properly.

Any thoughts on what could be causing this? I appreciate any help or advice you can offer!

[Armandorf]

Oil light is for pressure, not quantity.
Air leaks checkup and carb cleanup.
you should diagnose FIRST if you are too rich or too lean, you can use the choke for testing.
Accelerating on its own is usually an air leak, hanging idle maybe?

[haybaler]

Just a note on hanging idle.

I had a 2001 and a 2007 GS500, both with the later carbs and both suffering the hanging idle problem, 3,000 rpm, or turn down the idle set screw and stall, turn idle screw back to original position, 3,000 rpm..

I found in both carbs that the throttle plates were fairly open, so I turned the throttle set screw until the throttle plates were almost closed. Then I cleaned out the carbs and sprayed cleaner through the pilot jet hole until it came out in the venturi, to be sure not blocked. Then on 2001 carbs, drilled pilot jet with .34mm drill (careful, don't snap the drill bit!); on 2007 carbs, replaced 17.5 jet with 20 jet. Set the mixture screws to 2 1/2 turns, maybe 2 3/4.

Both bikes idle very solid at about 1300 rpm, after FULL warmup. Warmup time is still near 5 minutes.