For the first half of 1949 (February through June), the "K" model was produced, with what Simplex advertised as "Ten Major Engineering Developments". In July of '49, the "L" was introduced, and production continued through December of 1951.

ENGINE AND DRIVE SYSTEM

The "K" is the first to use the die cast aluminum cylinder with a cast iron sleeve. A new exhaust manifold bolts onto the cylinder, and the compression release has been moved to the front of the cylinder. The kick starter pinion gear now bolts to the flywheel.

Removable exhaust manifold

The new "Kwick Klean" air cleaner is used for the first time on the "K", and a three position detent for the clutch is incorporated, allowing for three "speeds".

The "L" model is the first model to do without the compression release. Since the kick starter has become standard equipment for starting, a stop switch is added to the stator plate allowing the rider a method of stopping the engine without the compression release. Late model "L" engines have narrower piston rings (5/64" wide). A Tillotson MT carb replaces the earlier "MS" version.
During 1948 production, the clutch pulley diameter was changed from 5" to 6".

CHASSIS

The "K" is the first to see the kickstand return to underneath the left floorboard (all "H", "48" and "J" models had the stand mounted rearward of the engine; "G" models had the stand located similar to the "K", but the "G" stand was a forged piece, where the "K" stand was simply steel tubing). It is also the first to have the flat plate-mounted handlebars instead of the bicycle gooseneck design.

Flat plate mounted handlebars

According to the order form, the "K" model was offered in the following standard configurations and colors:

• Model Code "K": All Black. Wholesale price was $187.13, with a Retail of $249.50
• Model Code "KT": Black with chrome fuel tank. Wholesale $190.88; Retail $254.50
• Model Code "KC": Black frame with chrome tank, fenders, and handlebars. Wholesale $194.63; Retail $259.50
• Model Code "KD": Chrome tank, rims, headlight, clutch pulleys, front and rear wheel hubs, handlebar plate and handlebar, front fork springs, saddle spring, front fork lock nut, hanger and rocker arm studs, BUT with black fenders
• All of the above and chrome fenders. Wholesale $202.13; Retail $269.50

Each of the above models were also available with saddlebags for an additional $11.25

The "L" is the first Servi-Cycle to have the two inch wide rims that continued until the end of production in 1960. Late "L" models have the later round taillight rather than the Do-Ray teardrop light, and also have curved front fender braces instead of two straight braces on each side.

The "L" model initially was offered in the same color combinations as the "K" model (see above). Beginning in late 1950, the colors offerred were:

• Standard Black
• Solid Blue with cream trim
• Solid Green with cream trim
• Solid Red with cream trim
• Solid Maroon with cream trim

Approximately 1000 "K" models were built in early 1949, with "L" models topping 10,000 units over the next two and half years.