Carb jet size? 74 carb on a desmogged 78 2F

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Jan 14, 2003
Wilton, Ca
Hoping one of the carb experts on here (Jim, Mark, other) can give me some reccomendations on what size jets I should be running in my 74 carb on my desmogged 78 2F (equipped with a non-USA dizzy w/ pertonix). Currently the carb has the following jets in it:

Main - 1.14
Sec - 1.80
Slow jet primary - 0.55
Slow jet secondary - 0.80
Power valve - 0.80

I have the following spare jets as well:
Mains - 1.18, 1.20, 1.24, 1.80
Slow jets (secondary only) - 0.60
Power valve - 0.50, 0.60, 0.80

The SOR jet size charts show that for a 78 2F carb the main primary should be 1.24 or 1.36 and the main secondary should be 1.38 or 1.71 so I am wondering if I should bump the jets up in my carb. It currently runs pretty well (minus the leaking air rail pugs that will be fixed soon), but if I can get a little more umph out of the motor (especially when pulling a grade) that would be great.

Sacramento = ~30' amsl, but I drive into the mountains for wheeling (5K amsl and greater).
Well, I don't think the FSM suggests you change to HA jets until you are above 6500'(?)
I currently run a '74 carb on a '77 2F bored .030 over and a 1.25 main jet. I did not have a 1.24 so I drilled an extra 1.14 with a dental drill that I had.
All this because I have not yet installed my fresh JimC rebuild of a 2F carb:eek:
It seems to run just fine with the 1.25.

Thanks Ed.
The 1.14 is the spare hi-alt jet. It should be stored in the primary bowl plug.
1.20 is the standard size in a 74 carb.
Run at least the 1.20. Like Ed says , it may run better w/ a little more than 1.20.

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