1951 Harley Davidson FL Panhead

Description

First introduced in 1948 as a replacement for the Knucklehead engine, the Harley-Davidson FL Panhead is a celebrated icon in American motorcycle history, representing the post-war evolution of Harley engineering and style. Powered by a 74 cubic-inch (1200cc) Panhead V-twin engine — so called because the distinctive shape of the bike's polished aluminum rocker covers resemble upside-down pans — the FL model offered improved performance and reliability over its predecessors.  

For 1951, Harley-Davidson introduced several mechanical upgrades to the FL, including a larger pinion shaft, chrome-plated piston rings, and machined rocker arms. These refinements enhanced durability and engine efficiency. Mid-year, the M-74B carburetor was introduced, further improving fuel delivery. Stylistically, the '51 FL featured new tank emblems and a range of vibrant paint options, including versions of red, blue, green, white, and black. Riders could choose between foot-shift and hand-shift configurations. 

The engine, of course, remained the star of the show. Harley-Davidson promotional material suggested, "Turn mountains into molehills … and miles into minutes.” 

This 1951 Harley Davidson FL Panhead has been with its current owner for 45 years. It recently underwent a professional rebuild and has retained its original engine, transmission, and frame while receiving new front end and replacement parts. 

Highlights

• 1951 Harley Davidson FL Panhead hasn’t been ridden since it underwent a full restoration/rebuild in 1990, which included: 

  • Finished in Persian Red paint over black leather seats 

  • Powered by a rebuilt 74 cu-in Panhead V-twin engine with S&S Super high-performance carburetors, originally rated at approximately 50 hp 

  • Four-speed manual transmission with chain drive to rear wheel 

  • Buckhorn-style bars handlebars with teardrop mirrors 

  • Triple headlight setup 

  • Air deflectors on the front fork 

  • Black leather spring-mounted pogo seat with rear fender-mounted buddy seat 

  • Dagger-shaped sissy bar 

  • Upgraded to 12V electrical system and lights 

  • New 120 mph speedometer and odometer 

  • Side-mounted SunPro PSI gauge 

• The chassis number (51FL8745) decodes as: 

  • 51 – 1951 model year 

  • FL – Model 

  • 8745 – Serial number

Features 

• Chrome accents on fenders, handlebars, and exhaust 

• Kick start and hand shift 

• Horn 

• Rubber-covered footboards 

• MT190-16 tires in front, 5.10-16 tires in rear 

Known Imperfections 

• Minor paint chip on rear fender 

• Kickstand chrome is worn 

• New tank emblems were introduced in 1951, but this restored bike does not wear any  

Included 

• Panhead Service Manual: 1948-1957 Rigid 

• Antique license plate 

• Spare heads, cylinders, original tank, and some other items 

Ownership History 

The Michigan seller of this 1951 Harley Davidson FL Panhead has owned it since 1980. It has been used as a show bike and, due to health reasons, has not been driven since its restoration in 1990. It has been stored in the seller’s basement, and he says the kick starter has been used regularly to turn the engine over and prevent damage.