Originally posted by rc_alan
Why would you want to switch from a Picco carb to a OS 10c??? You might be asking for problems... ??? What OS. engine uses the 10c carb??? If anything, if you had to switch carbs and you like the OS. brand, I would use the 10j turbo 3 needle carb... And that's if it fits.... If you're having tuning problems... It might just be your settings... So back the my first question... Why do you want to switch carbs in the first place??? There's a good chance that you'll have less power using the OS. carb... But that's for another thread... 
RC_Alan
the os carb thats 3 needle is the #11A slide-valve carb.The 10j is the 2-needle!