Altitude Adjustment

[ROOTES66]

Yay! I finally took possession of my 66 Alpine, just in time for a snowstorm.
My question, as a new member groping in the dark, is how to adjust my Weber carburetor for mile-high altitude (5280 ft), coming from 942 ft, and possibly a timing adjustment as well. The transporter claims it ran fine when he loaded it onto his trailer. It runs pretty rough here in the high dessert. So my first instinct is that my cocky-cockney-car needs an "altitude (attitude?) adjustment".

I know the Weber carburetor is a modification (a good one, I understand), but it is a very common modification/upgrade, and I posted here under "stock", since everything else is pretty much stock.

I would guess there is a thread someone can point me to, or just a voice of experience to lead the blind. ~Chuck

 

[beamdream]

I know this is a late response, but if you are still wondering I quote from a Weber service manual "normal jetting is correct anywhere between sea level and 5000 ft." so I would imagine at your stated altitude I would leave things alone, cant see the extra 280 ft. making much difference.

As to timing, perhaps you might try a vac gage to get the best setting.

 

[Nickodell]

Many possible causes of roughness, of course, but if you suspect "altitude sickness" it would manifest itself as over-rich mixture, which would probably show up on the plugs as soot. It couldn't hurt to try smaller jets.