Help please? :)

[Henson93]

So I have a k3 600,
Cleaned the fuel filters out best I can and cleaned the jets run 4 full tanks of shell nitro with injector cleaner in to really make sure everything is clean. It’s not taking in any extra air from anywhere either,

it has a flat spot in the revs at low revs. When in dealer mode the tps position is showing it’s moving up and down from middle to top to middle then bottom and so on,

I can only imagine it’s the throttle position sensor just thought I’d ask here first any thoughts and or advice?

 

[Engenia]

It's over 20 years old so it's highly likely the TPS wiper has worn through, making it intermittent. You could check it by measuring the voltage at the wiper with the ignition on, but no running. If you move the throttle smoothly from closed to wide open the wiper voltage should vary smoothly with it. An intermittent wiper will cause the voltage jump about as it changes position.