If the carburetor was originally sold for your altitude it would
have been leaner, with thicker metering rod. It's adjustment effects
both power and mileage. I really don't know if you may richen the
mixture and solve pre detonation at altitude. If it was spark knock then
of course that would be solved by retarding the timing.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

LeeB103926 wrote:
>
> I adjusted the Napa kit for my '73 Carter YF on a 258 to exactly the same point
> you are describing -- very near the inner end of the possible adjustment. It
> runs well to about 12,000ft. Driven carefully (to avoid acc pump input) it
> runs to 14,000ft with a little smoke from being too rich.
>
> Question for others: how do you tell by power or mileage or ping/knock if the
> metering rod is adjusted correctly?
>
> Lee
> Colorado Springs
> original '73 CJ5

 

If the carburetor was originally sold for your altitude it would
have been leaner, with thicker metering rod. It's adjustment effects
both power and mileage. I really don't know if you may richen the
mixture and solve pre detonation at altitude. If it was spark knock then
of course that would be solved by retarding the timing.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

LeeB103926 wrote:
>
> I adjusted the Napa kit for my '73 Carter YF on a 258 to exactly the same point
> you are describing -- very near the inner end of the possible adjustment. It
> runs well to about 12,000ft. Driven carefully (to avoid acc pump input) it
> runs to 14,000ft with a little smoke from being too rich.
>
> Question for others: how do you tell by power or mileage or ping/knock if the
> metering rod is adjusted correctly?
>
> Lee
> Colorado Springs
> original '73 CJ5

 

That carb does have a high altitude adjustment on some of them. Some
screw that turns 2.5 turns from high to low altitudes. I have no idea
what it would look like though.

To check the carb for rich lean condition, you take it for a good drive
preferably steady on the highway and stop and check the plugs.

Too rich will have black/brownish sooty plugs and too lean will have
whitish plugs.

I messed with mine once and noticed a drop in highway power right away.
I think I was lean because if I fluttered the gas pedal which gives
shots of extra gas via the accelerator pump, I got a noticeable power
and speed increase.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

LeeB103926 wrote:
>
> I adjusted the Napa kit for my '73 Carter YF on a 258 to exactly the same point
> you are describing -- very near the inner end of the possible adjustment. It
> runs well to about 12,000ft. Driven carefully (to avoid acc pump input) it
> runs to 14,000ft with a little smoke from being too rich.
>
> Question for others: how do you tell by power or mileage or ping/knock if the
> metering rod is adjusted correctly?
>
> Lee
> Colorado Springs
> original '73 CJ5

 

That carb does have a high altitude adjustment on some of them. Some
screw that turns 2.5 turns from high to low altitudes. I have no idea
what it would look like though.

To check the carb for rich lean condition, you take it for a good drive
preferably steady on the highway and stop and check the plugs.

Too rich will have black/brownish sooty plugs and too lean will have
whitish plugs.

I messed with mine once and noticed a drop in highway power right away.
I think I was lean because if I fluttered the gas pedal which gives
shots of extra gas via the accelerator pump, I got a noticeable power
and speed increase.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

LeeB103926 wrote:
>
> I adjusted the Napa kit for my '73 Carter YF on a 258 to exactly the same point
> you are describing -- very near the inner end of the possible adjustment. It
> runs well to about 12,000ft. Driven carefully (to avoid acc pump input) it
> runs to 14,000ft with a little smoke from being too rich.
>
> Question for others: how do you tell by power or mileage or ping/knock if the
> metering rod is adjusted correctly?
>
> Lee
> Colorado Springs
> original '73 CJ5

 

That carb does have a high altitude adjustment on some of them. Some
screw that turns 2.5 turns from high to low altitudes. I have no idea
what it would look like though.

To check the carb for rich lean condition, you take it for a good drive
preferably steady on the highway and stop and check the plugs.

Too rich will have black/brownish sooty plugs and too lean will have
whitish plugs.

I messed with mine once and noticed a drop in highway power right away.
I think I was lean because if I fluttered the gas pedal which gives
shots of extra gas via the accelerator pump, I got a noticeable power
and speed increase.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

LeeB103926 wrote:
>
> I adjusted the Napa kit for my '73 Carter YF on a 258 to exactly the same point
> you are describing -- very near the inner end of the possible adjustment. It
> runs well to about 12,000ft. Driven carefully (to avoid acc pump input) it
> runs to 14,000ft with a little smoke from being too rich.
>
> Question for others: how do you tell by power or mileage or ping/knock if the
> metering rod is adjusted correctly?
>
> Lee
> Colorado Springs
> original '73 CJ5