Needle Comparison--49-state vs. Cal.

[Vmaxattacks]

Maybe this can be part of the sticky..:eusa_dance:

Anyway, I wanted to do some calculated comparison between the 49-state needle, 5EZ43 & the California counterpart, 5EZ50. I used my RAM optical comparitor here in the lab to measure the "business end" of the two and I then dialed in all of the calcs. The 49-state versions are fatter and with a less acute slant height than the Cali needles meaning that they will tend to be a tad leaner overall. I guess that one could use the Cal needles to fatten up the mid-range without the need to add a shim to your existing 49-state needle. Just an observation.

Here are the results:

The 49-state needle has a tip diameter of .044" a dimension of .095" right after the taper whereas the California one has a tip of .041 with the same .095" base.

The 49-state has a tapered height of .322" whereas the Cali needle has a height of .341.

The following are rough but good enough for comparison...



s = slant height
V = volume
L = lateral surface area
B = base surface area
A = total surface area


5EZ43: (49-state)

s = 0.32548 in
V = 0.00076 in3
L = 0.04857 in2
B = 0.00709 in2
A = 0.05566 in2


5EZ50: (Cal)

s = 0.34429 in
V = 0.00081 in3
L = 0.05138 in2
B = 0.00709 in2
A = 0.05847 in2

As you can see by the "slant height" and the "volume" calcs, the California needle lends itself to less volume over a given length which in turn will yield a broader and richer mix across the board.

Thought this might be of some use to you all..
..Bud

 

[naughtyG]

I'm a bit confused by this. Why would the Cali needle be richer, when Cali is the 'cleaner' state for emissions? Shouldn't it be the other way round?

 

[m-cman]

I'm a bit confused by this. Why would the Cali needle be richer, when Cali is the 'cleaner' state for emissions? Shouldn't it be the other way round?

Maybe the Cali jets are smaller?

 

[maleko89]

Jets are the same. Japaneze models do have different jetting though. According to my notes Cali and US49 needles are the same. The 5EZ50's mentioned I have down as Canadian needles.

 

[Vmaxattacks]

Nope...Vmaxoutlaw site has them listed wrong. My 94 purchased new here has 5EZ50 needles, Also specifies it in the manuals. I have read alot of reference materials until my cranium is ready to explode:bang head:US 49 are 43's Cal are '50's.
The PAJ is a #100 instead of a #90. That seems to be the only diff other than the charcoal can and the nipple on the front carb. Maybe the cams ARE ground different..who knows, But certainly the surface area of the 49-state needles are more in comparison so they are leaner but in less throttle opening.

Taken from the FSM

Model
Carbureror
I. D. Mark
Main jet
Main air jet
Jet needle
Needle jet
Pilot jet
Pilot air jet
Pilot screw
Pilot outlet
Bypass 1
Bypass 2
Bypass 3
Valve seat size
Starter jet
Starter jet
Throttle valve size
Fuel level
Engine idling speed
Vacuum pressure at idling speed

VMX12
1FK02 (USA), 2WF 02 (California),3LR 01 (EUR)
#152.5 (USA, California), #150 (EUR)
82.0
5EZ43-1 (USA), 5EZ50-1 (California),
5EZ19-3 (EUR)
Y-0
#37.5 (USA, California), #42.5 (EUR)
#90 (USA),#100(California), #95 (EUR)
2-1/4 (USA), 3 (California), 2-1/2 (EUR)
0.9
0.8
0.8
0.9
1.5
#45
#0.8
#125 (USA, EUR), #130 (California)
15 ~ 17 mm (0.59 ~ 0.66 in)
950 ~ 1,050 r/min (USA, EUR),
1,050 ~ 1,150 r/min (California)
26.7 kPa (200mmHg, 7.87 in Hg) (USA, EUR)
33.3 kPa (250mmHg, 9.84 in Hg) (California)
- 3

 

[one2dmax]

What are the needle tolerances? Might be simply some of the difference is the tolerance of them.

Sean

 

[gamorg02]

my thoughts too sean

 

[naughtyG]

I do wonder still. On something like needles, I would have expected pretty low tolerances, just as I would expect in jet sizes and other critical carb parts.

I guess the way to tell would be to examine a few of each..

 

[Vmaxattacks]

What are the needle tolerances? Might be simply some of the difference is the tolerance of them.

Sean

There are very distinguishable differences between the two as I would highly doubt that they are at anything but the nominal tolerance given the fact that these are spun on a CNC.

 

[gamorg02]

maybe they are from different batches too. so the tolerance within a batch is one thing but between batches may be different?