I'm just in the process of "rebuilding" my Carbs and noticed that the main jet sizes are quite a bit smaller (114/116) than the stock sizes (130/132), even though the sparks plugs look OK. I think the needle has also been replaced at some point as it's one of those adjustable ones and it also looks thinner than the stock ones.
I guess the bike isn't running lean due to the fact that the needle is letting more fuel into the carb/engine, despite the main jet being smaller than stock?
I'm not sure if I should replace the main jets and needles with stock ones or stick with what seemed to be working OK......any thoughts guys?

 

Max power is about -15-20% less petrol than stock.
But, not as tolerant of sitting and clogging.
If it’s working, then leave it alone.

 

Thanks, that explains the smaller main jets then

 

what you probably have is a Dynojet kit. this usually came with a needle that has 5 grooves in it and an adjustable E-clip which allows you to raise or lower the position of the needle. these kits also came with new jets (usually of a different size than STD) and sometimes included instructions on how to block off or restrict certain ports for optimal performance. if you aren't having problems, LEAVE IT ALONE. just monitor the plugs and make sure you don't run it lean.

 

Exactly, the needle has the grooves you mention with a circlip of some sort that can be moved to raise or lower the height. I'll keep the setup "as is" then, as it should be giving me max power, based on what Dannoxyz said

 

In general, DynoJet kits are for following mods:

Stg-1 = free-flow intake and full-exhaust

Stg-2 = all above along with big-bore high-comp pistons, cams, head-porting

 

Thanks for the info, I assume that it's just a Stage-1 upgrade as it has a "free flow" air filter and "performance" exhaust.