BS34... small round main or large round main jet?

Hi,

I currently tuning my Mikuni BS34 ...

I have large round main jet but after a few site ... its says that only small round main jet are compatible to this model of carbs?

I have the two type of jets ... they look identical except top of the jet is larger the other one is smaller...

Quote from streetperformance.com

CV CARB JETS SMALL ROUND MAIN JET Fits BS series CV carbs

and for large round main jet (the one i use now)

LARGE ROUND-TYPE MAIN JET Fits RS and HS

Did they screw up something or i'm running with the wrong main jets ?

EDIT:

Also here (example):
www.dscmoto.com/dirtbikeparts/mxsmallrou...tors-TR-42-1957.html

MX Small Round Main Jets Size 155 Fits BS Series CV Carburetors

regards,
laurent

I have seen the same $hi+ Yet I have never seen the small jets being used on a Kawasaki. I have on the other hand seen them on h0nd@. They do flow differently than the large head jets.

Thanks Otakar! You are the king!

regards,
laurent

Here's a great site to identify all types of Mikuni and Kehin Jets.

www.pjmotorsports.com/

And here is an awesome jet flow cross reference table :

www.jockeyjournal.com/forum/showthread.php?t=64769

Ive interchanged small head and large head jets you simply need to factor in the flow rating differences between the two styles of jets.