Right, seems I'm not the only one with this problem but I can hopefully after tomorrow shed some light on the cause. Basically on start up my bike makes a high pitched chirping/squeaking sound as the start up sequeance begins and again as it finishes. It also happens if I blip the throttle as the revs return to idle. After researching the net it seems that this squeak is causes by a lack of grease in the exup vlave which is prone to seizing. I called up Jack Lilley again today to say I want it looking at whilst I still have a few weeks left of my 3 month warrenty. (Bear in mind this is the 4th time its been into their workshop in the space of under two months). I'm going to have them look and listen to the valve and the noise and see what they suggest as a possible remedy. I'll be sure to keep you updated which might be useful to the others with the same irritating noise.