Petcock upgrade Neccessary

I was doing quite a bit of reading through the forum and could not find a clear answer.

At what point does a factory petcock not flow enough? I am moving to a set of RS36 carbs and would like to get my ducks in a row before installing.


1200cc + ?
1327cc +?
120 hp +?
130 hp?
Mile long runs wide open?


Is there a standard benchmark or indicator that you would use to decide when an upgraded petcock is needed?


 

Or another bit of data, does anyone know of any charts that reference how much fuel a kz can consume at wot ?

Going to be wide open, winding out the rpms for 30 seconds plus every run.

Fit a Pingle.

I agree, fit a Pingle with single outlet then uses their filter with one inlet and two outlets to each bank.

A single outlet Pingel with 5/16" ID lines, Emgo sintered brass filter, and "Y" fitting is what I am using for my 1200 street engine (VM33 Smooth bores) I am shooting for 115-120 HP at the wheel.

My 1327 drag engine (16:1 comp) is using a dual outlet with 5/16" lines to feed 40mm Lectrons. Most guys run RS40's on 1327 to 1428 for street engines, 38's if you have a small valve head (37/31) I am running 40 Lectrons because that's all I could find used at the time, waited for 4 years for some 38's that never appeared. That engine is pretty tame so maybe 140-145 HP to a 7" slick.

I have some RS34's and the fuel tees fit 5/16" line, those tees only have one part number in the Mikuni catalog so even RS40's use a 5/16" line, the tee ID is probably 1/4" (never measured it)



The internal fuel passages are the limiting factor for fuel flow, that and the needle valve assembly size. I have never see a fuel flow consumption chart at WOT as I don't think too many motorcycle engine builders are worried about it.

If I was running a 1327-1428cc street engine with RS40's I would run a dual outlet Pingel with a filter on each line feeding the carbs. With two lines you should never run out of fuel flow.

Fantastic,

Thank you all. 

Pingel will get my money this afternoon!