Update as promised, she is running again. Got old style pickup cover off ebay £10(bargain) and fitted. Thought i would check carbs again and found that i had nipped another o ring in one of pilot jets, so replaced it and checked all others. Built it back up again and she fired up first time. Dont know if it was pickup cover or o ring or both but seems to run fine now, gave it a good blast. Now need to balance carbs and get new fuel tap, cant get pattern part,or diaphram kit as its sealed unit , was sold by a bike parts stockist a GS500 tap with separate diaphram but not enough room to fit. So on lookout for another one.
Thanks for all help lads

Good to hear. Ive got a tap if you need!
Chris.

How much do you want for fuel tap mate?
Nick

Well that didnt last long!!!!

Bloody thing playing up again,starts when it wants and runs fine but turn it off and try again it wont start. Rapidly loosing interest in it.

Nick