[ihc] More on musical carbs

["Allan Ericson" <lowvolt@xxxxxxxxxxxx>]

Digesters-

Okay, the preliminary data is in.

I bought a new carb, put in on my 73 travelall w/345, got 12 mpg coming home
from CO. It had a manual choke, so I pulled the carb off of my 75 scout and
installed it. Put the carb with manual choke on my pickup, since that's what
it's supposed to have. Carb that was on there was leaking.

Travelall mileage went up from 12 to 13. This is odometer miles, even though I
switched from 235/75/R15 to 31x10.5 tires, so I'm guessing slightly better
than the 13 that the odometer shows. Okay, we'll call it 13 on the highway for
giggles and grins, a gain of a little over 8%. We intend to try it again
tomorrow, and can compare with more new data.

The pickup truck with the leaky carb was getting 10 to 10.5 mpg. With the new
carb, it's a solid 8. Just 8, consistently, after two tanks of gas. 20%
reduction in economy. Manual transmission, can't blame it on a torque
converter.

It does not smell like it's running rich, although I haven't really taken time
to sniff closely. The idle smoothed out a whole lot, and so did accelleration.
Timing is set so that it pings going up hill at lower altitudes (Phoenix), but
not where I live, so I'd say it's at least close.

Any ideas? That gas is going somewhere, but I'm not sure where. The answer may
be staring me in the face, but I surely can't see it.

-Allan