Main reasons i have for wanting to change the jetting or gearing is that its very boggy low down and drinks petrol like jocky wilson sinking pints.. 
Currently getting 38 -42 on 8 litres, also wants to die every time you come to a stop meaning constsnt popping of the throttle... 
Iv done plug tests and its jet black and is a lot richer than me.. Think the final ratio for a Franspeed race is 4.9? although the current 18x47 (5.2) does seem fine and pulls in all gears. If I was going to go for a 4.9, what would be better 48x16 or 46x19 as this should let me still be able to use the same chain?
Have the following:
RB20 kit
Dellorto VH/SH 30 flat side
60m crank
1.4 squish
Franspeed race
18 x 47 = 5.2
indian gp 200 box
Cheers
Sef