Tuning Carbs for Cam

[Deus Ex]

I put a lumpier cam in over the weekend and noticed that at high RPM it seems to starve for fuel a little, my local Motorsport shop told me i need to replace my main jets and maybe air correction jets to get the most out of it. At a high $$ might i add. So i stumbled on this forum, should save myself some cash hopfully.

Im running Triple 45mm webers (im not that technical so please excuse me if i dont have all the tech details, assume they are standard i guess).

32mm Venturis

so i guess i have..130 Main Jets and 180 air correctors (roughly)

272 cam with 318 (cam only) duration

L28 with flattops (2.9)

Ported and Polished P90

2.5 Exhaust

If anyone could give me a rough idea that would be great otherwise, ive printed out this thread and shall sit down with my mechanic friend and we shall work out the details. Also, is there really any advantage to getting larger venturies, as these are quite expensive. It also really doesnt like to drive around ranging from 2-3rpm, it just seems to stutter and such. I am aware i have no vacuum advance, but i am assuming i just need to tune the carbs to the Cam. Or are they supposed to run like this with a more agressive cam?

Now since its starving alittle for fuel up top (well surging is more the word) does this mean i require larger air correctors or main jets? understand that new Air corectors give the top power, but thanks for pointing out that i need smaller ones. So if changing the air correctors will give me more smoothness and power delivery up top, and mains will give more throughout, is there any point in changing both, or will i need one or the other?

So if anyone has a similar set, a rough guide for specs would be great

Thanks

[g260]

DX,

If you have a look at the carburation heading in this site it may assist you a bit. Even though he is running 40's instead of 45's, you may get a starting point.

http://www.geocities.com/jasonparuta/

HTH.

g260

[gramercyjam]

Here is a thread on triples you should read. I also think a good book on webers is a must have.

[gramercyjam]

Never mind. It looks like you already found it.

[redneckz II]

:beard: Try going to a 37mm Venturi and 4.5 aux. The 37mm will help in the upper RPM range. Also check out the HybridZ.org site and check out the the info on the L-6 engine file sticky. It has some great info on jets for the carbs on it.