need to drill out main jets but dont no how big to go

Go on, give us a hint. Carb(s) engine+state of tune? (1.7 xflow?), current jet size?

Not that anyone can give you more than a guess, a good rolling road is the only way to tell for sure.

for xflow 1.7 big valve head zx6 carbs

[Edited on 18/6/07 by dave-69isit]

What size are the carbs?

36mm ? 38mm? .

What size are the standard main jets?

No one can guess , but I'll be bold and make prediction that you will end up with something between 140 and 180.

You could also ask : Deckman001 I believe he has those carbs on his x-flow.

[Edited on 18/6/07 by Surrey Dave]

the carbs are 36mm