In 1951  only four big twin models were offered.  The EL and FL models were continued.  ELS and FLS sidecar gearing models that where offered in 1949 but not in 1950 where brought back.    production of the low compression models E and F was discontinued. Also in 1951. new style gas tank emblems, chrome plated piston compression rings and rocker arms were machined with pushrod sockets. In mid 1951 the M-74B carburetor was introduced along with a larger diameter pinion shaft.

 

1951 speedometer

1948-1952 speedo
1948-1952 speedo

 

1951 gas tank emblems

harley davidson gas tank emblem 1951-1954
1951-1954 emblem

Here are some great sources for detailed information about Harley Davidson’s 1951 Panhead

hydra-glide.com The panhead and flathead site

How to restore your Harley-Davidson by Bruce Palmer 111

The Harley Davidson Panhead service manual 48-57 rigid

Riding vintage website

the Jocky Journal web forum

1951 models
model engine type actual displacement compression factory options
EL  sport solo 61 c.i.high compression 60.32 c.i. 7.0:1 __
ELS  sidecar twin 61 c.i.high compression 60.32 c.i. 7.0:1 S = sidecar gearing
ELF sport solo foot shift 61 c.i.high compression 60.32 c.i. 7.0:1 F = foot shift
FL  sport solo 74 c.i.high compression 73.66 c.i. 7.0:1 __
FLS side car twin 74 c.i.high compression 73.66 c.i. 7.0:1 S = sidecar gearing
FLF  sport solo foot shift 74 c.i.high compression 73.66 c.i. 7.0:1 F+foot shift

NOTE: the ” F “ denoting foot shift will not be stamped in serial number.

NOTE: the ” S denoting sidecar gearing will not be stamped in serial number.

1951 models available colors
paint stripes speedometer
black _____ bluish gray center. cream white mph numbers. red indicator
1951 metallic blue _____ _____
metallic green _____ _____
persian red _____ _____
rio blue _____ _____
silver _____ _____
white _____ _____