Idling issues when engine is warmed

Hey Iv been having an issue with my bike, an 82" kz250 where it starts and runs fine until Iv been riding it for about 10-15 minutes then it starts to drop out when idling. It's fine if I keep giving it revs. But when I'm waiting at lights and stalls after a few seconds when I don't give it any throttle. Any ideas? Here's a photo of the spark plug

Would suspect insufficient valve clearance as causing the reported symptoms.

Good Fortune!

Thanks for the tip Patton, I went ahead and adjusted the valve clearances accordingly. They were too tight. It definitely starts heaps better now but the other problem still persisted when the engine gets hot. It also backfires and pops on deceleration

Sync the carbs.
Steve

Thanks Steve but it's only got one carb

My bad. Popping can be a lean condition, timing, air leak or many other things. Pic of the plug?
Steve

Here's one

Difficult to see in the avatar photo but is there an airbox on the bike and is that an open exhsust ?

No the original air box has been replaced with a pod filter and did you mean open exhaust?

Popping from the exhaust on deceleration can result from a too lean pilot circuit, which might be due to the pod filter (as opposed to the stock air box with stock filter).
Could try turning the pilot screw 1/2 turn out, and test ride.

This presupposes that the stock anti-tamper plug covering the pilot screw has already been removed.
But if not, there's an easy method to remove it

Backfiring through the carb can result from a too tight intake valve clearance.

Good Fortune!

Problem solved: it was running lean. I adjusted the fuel screw and it idled way better now. Thanks heaps for the help

Hi guys, I'm having a similar problem with my Z200. Could you describe how you adjusted the fuel screw? Did you just try different settings?