IF I remember correctly the KA has an idle control valve which is located on the top of the engine. There should be 2 8mm nuts holding it on. (this is from memory - I had a KA a couple of years ago and I did this). You need 'Carburetor Cleaner' - any make will do, Halfords sell it for £5ish. Spray this around the metal casting part you have taken off (need to unplug it). The carbon deposits should be cleaned from inside. The spray will self evaporate quickly, so once dry reattach. Just to clarify, the part you need to clean should be a metal casting that is attached to a black plastic piece on the fuel injection area on the top of the engine (near the rocker cover).
Hopefuly the clean should do the trick, otherwise it will need replacing - you could easily fit it yourself to save money.
Hope this has helped!!
Ex. KA owner, November 2008
