In the days when Harley only made carb bikes every model across the range will have had the same tap, whether it was a Sporty with a peanut tank or a dresser. The reserve on each bike will be different, simply as a result of the different shape of the tank. The only 'spec' of any use would be the height of the reserve tube, but that won't help work out the reserve available, that can only be reliably measured once the tap is installed.

Buy a Pingle and all your problems will disappear......

 

Besides the petcock..their are other factors that can affect reserve. Early Softail tanks had the petcock between the cylinders...which put it towards the front of the tank...if you lower one of these bikes in the rear...you can trap 3/4 gal or more...that you cannot get out regardless of the petcock you run. At some point they moved the petcock to the rear of the tank..where it should have been to start with...Food for thought.

 

Get a pingle. The most best (hope that is the correct grammar ) fuel petcock on the market. Mines been on 20+ years. Only time I touch it is to turn the gas on and off.

 

The best test is to keep track of your mileage and run it until it stalls. Put it in reserve and run it until it dies. Check milage.
Oh, carry a gallon to get you going and get to a gas station.
This is the only sure way you can answer your own question.
You're in Cali, there should be a station on every corner.

 

There's a station at every corner on average but this was in the nice part of the coast. They don't like to have stations like "the others".

 

It isn't, but it does well enough!

 

Pingel reserve is 8 miles, 1 gallon tank in saddle bag is 30 more babied. The gallon saddle bag tank got the White Bike out of the Smokey Mountains to Cherokee

 

What did you do to your Pingle to only get 8 miles out of the reserve????????
I get between 30 and 40 miles out of mine and that's after I cut it 1/2"ish shorter.

 

Installed a friken 127" that was on steroids and the only time I used reserve, it is pulled back some right now and estimate 30 mpg babied

I always win by a gallon on the "how much fuel did you use" when running hard with good running bikes

 

Gotta feed all those ponys, whether you use them or not.

I got 21 miles on reserve from my 80". I averaged 34mpg, for 15 to 20+ years...