Update of tonights antics:
Found an old SBW thread with Bilko and others discussing the really small main jet on the 200 Cosa.
Cleaned it but didn't take much notice of it really,
Went and had a good look and it was a 96, swapped it with a 115 main and it revs and pulls clean as a whistle (never understood that phrase),
So, the big test is a 6 mile ride to the MOT station tomorrow, and fingers crossed the blocked filter was the restriction, which then allowed the undersize main jet to be lean.
2 faults but from the same cause
If it performs well, I will find a 118 and pop that in and jopefully all will be good.
Watch this space.
Shaun.