Technical: Gas Tanks
Jack Raino, Jerry Raino, “Magneto Sportster”, Dave Carleton, “Simon”, “The French Owl”, Dave Hennessey

1958 - 1969 XLCH

This article is under development

1948 - 1966 Hummer-series

he 1948 Model 125 (the first of the “Hummer-series”) exhibited a beautiful new gas tank, unlike any found on previous Harleys. The Hummers got almost 100 miles per gallon, so the small tank was more than adequate.

The petcock on this bike is located at the left rear. This is the same location as would be used later for the KR.

The styling of this tank was so good that, with a few modifications, it would find itself on several decades of K-models and Sportsters.

1954 - 1969  KR Racers

61000-54 - The KR racers originally used the production K gas tank. These were larger and heavier than what was needed for many flat track races. The Hummer tank, holding 1-3/4 gallons, was just about the right capacity, and its narrow shape was right for racing.

It needed some work to be adapted to the KRs. The Hummer's tank has a very high tunnel, since the Hummer's engine is quite short. For the KR, the tunnel was lowered - increasing the capcity to 1-7/8 gal. The Hummer's gas cap, offset to the right, was moved to the center for the KR. One thing that did not need to be changed was the petcock bung. The Hummer bung is on the left side near the rear of the tank. The K's Linkert carb is on the left side of the bike.

The 1953 Competition brochure shows an option of a 1-7/8 gallon tank on KR and KRTT, but not on KRM. This was probably the 61000-54 tank.

The KR parts books show:
1954 - the single-bung 61000-54 racing tank
1956 - the double-bung 61000-54A production tank
1959 - the double-bung 61000-54B production tank
1968 - the 61000-54R racing tank.

1958 - 1959

61000-54A - The KR tank would easily adapt to the new Sportster XLC and XLCH - the only problem is the Sportster's DC carb is on the right side of the bike.

The KR tanks were modified by plugging the Hummer bung, and welding in a new bung on the right middle (the XL bung).

The -54A and -54B (below) double-bung tanks were used up until 1965 so they would be compatible with both Sportsters and KRs.

1960 - 1965

61000-54B - Double-bung tank. The protruding ridge on the right side is now separated into two parts, and the XL bung is now “factory-installed” in the tank bottom.

The Hummer bung is plugged with an “allen wrench”-type plug.

1958 - 1965

662 - On 1958 - 1965 “double-bung” tanks, the Hummer bung was plugged with this plug. It is listed in the Parts Catalogs from 1959 through 1967. The 1967 Catalog shows it as fitting 1958 - 1965 XLCH.

While this ilustration shows a plug with a square wrench head, most observed tanks have a recessed hex for an “allen” wrench.

1966 - 1969

The 61000-66 and 61000-54C were the same tank, and were used on production bikes from 1966 through 1969.

  1. The Hummer bung was removed.
  2. The XL bung is slanted at an angle (maybe 30-degrees), so the petcock does not hit the Tillotson carburator's insulator block.
  3. There is a vent fitting at the front for the Tillotson carburator.

61000-66 - was only listed in the 1966 Parts Catalog

61000-54C - A 61094-66 Rubber Cap, gas tank vent line was provided for use on pre-1966 bikes when sold as a spare part.

Jack Raino's Double Bung Collection

Things to notice: Use the Super-Size button! The light blue tank has an unusual Tillotson vent. The light blue, gold, and yellow tanks appear to have factory-interrupted ridges around the XL bungs, and the bungs look more “factory installed”. The dark blue and rust-colored tanks appear to have “afterthought” XL bungs. You may be able to spot other differences.

Here is what the Parts Catalogs show

Part # Fits
1958 silent  
1959 61000-54A 58-59 XLC and XLCH
1960 61000-54B 58-60 XLC, XLCH (-54A replaced by -54B)
1961 61000-54B 58-61 XLC, XLCH (-54A replaced by -54B)
1962 61000-54B 58-62 XLC, XLCH (-54A replaced by -54B)
1963 61000-54B 58-63 XLCH
1964 silent  
1965 61000-54B 58-65 XLCH
1966 61000-54C 58-65 XLCH
61000-66 1966 XLCH
1967 61000-54C 58-67 XLCH
1968 silent  
1969 silent