Expert: Dan Liddy - 10/6/2004

Question
Hi,
    Can you please give me some basic instructions and the specific steps that I should follow to tune  a carburator so that I can get the best performence ?

(It would be better if you can relate to Japanese cars.)

Thanks.Have a nice Day!  

Answer
Hi Shamila:

Carburetors started disappearing off street cars around 1975-76. Nearly all modern cars now come equipped witih fuel injection systems that are not easy to  modify for performance.

That being said, the first thing one should do is remove and replace the air filter. Preferably with one supplied by  K&N filters. They allow more air to enter the system and allow the engine to breathe more deeply.

Next you can look into changing the main fuel jets, and then the air regulator jets to either enrich the mixture , or lean it out some.

One thing that should really help it is to add some ducting from the front of the car to insure that the carb is getting a generous supply of cold air. This can make a big difference in performance, espepcially on hotter days.  

If the car is to be used for racing only there are a few more things like removing the choke plates (brass flapper thing right in the top of the openings). This will make it difficult to start, but allows a tiny bit more air to enter.

Once those things are done, there really isn't much more to do to them.  If you are a performance hobbiest, you would gain more by looking into a high performance exhaust system, high energy ignition system, and perhaps a mild modified camshaft.

Working on carburetors is truely a black art, involving, luck, withcraft and Voodoo .  I've been racing for nearly 45 years now, and still have carburetor problems that baffle me for a time.

Good luck with your project.

Dan Liddy
Sarasota, Florida