Harley-Davidson 1931 model DL 742 cc side valve V-twin frame & engine # 31DL2575
The company introduced the side valve concept for the V-twins for the 1929 model year when the 45 ci model D was introduced.
A year later the F head big twin was replaced by the side valve 74 ci model V.
The model D was sometimes referred to as the “three cylinder Harley “, because of the remarkable vertical position of the dynamo.
The twin bullet headlights are another special feature of the early 750 cc model.
Several versions were marketed, the D had a compression ratio of 4.3 : 1 and a power output of 15 HP. The DL had a somewhat higher compression ratio of 5.0 : 1, which gave 18.5 HP. Top of the range was the DLD which got 20 HP @ 4000 rpm with a ratio of 6.0 : 1.
Standard paint finish was olive green with maroon striping with a centre gold stripe. Handlebars and wheel rims were finished in black.
Potential buyers could choose though from a range of new colours: black, maroon, grey, blue cream and coach green, all at extra cost.
In 1929 in all 6856 750 cc models were sold, the 1000cc models were still more popular with around 13,000 machines being produced.
Among the new features for 1931 were a single 7 inch headlight, a larger and more effective band rear brake, a modified clutch and generator drive.
The formerly nickel plated parts were now chromed. 1931 would become the last year of the model D: a redesigned 750 model
“R” would become its successor. (Source: “Harley Davidson, all the Motorcycles 1903-1983” by Matthias Gerst.)
This DL has been restored immaculately and is a smooth running machine.