hey guys I'm playing round with this 3k carby, I'm gonna go and get some 4k jets today or tomorrow. i got the middle piece of the carby and i have forced the venturi chokes out of it. the primary venturi is 19mm and the secondary is 24mm. now both the ports on the carby base are 28mm. What my idea is to see if theres any larger aisan carbs out there with the same bored 28mm ports, but run larger sized venturi chokes, letting more air,and fuel through the passage. I was thinkin of seeing if there was say a 20 or 21mm for primary, and a 26mm for secondary. i would jet it to suit

 

Is this worth tryin or should i just put another carby on it. Has anyone played round with the venturis?

If you get a carby off of a KE70 they have bigger, throats, and venturies along with bigger jets. But you have to plug or block all the extra emmisions ports. I have one on my road car now and runs like a charm with a worked 3K.

If you put bigger auxiliary venturies in it you will most likely make it run shit and give it a masive flat spot due to the too low a pressure difference you will have created.

 

You will find a smaller auxiliary venturi size will give you an increased fuel flow, but then may cause too rich a mixture at wide open throttle..

hey, i have a 3k carby, i lathed out the secondary venturi, can't remember the exact size but can find out, it still runs standered sized jets, it made a big difference though, as you can really feel when the secondary open's up, it also gives a deeper induction noise when its opened.

hope that may help.

Edited February 25, 200917 yr by sam k

that would be good if u could find out mate, I'm thinking of playing round with different sized secondary chokes to see what works out i guess its just trial and error