1957 AJS 18CS Cold Start

The 1957 AJS 18CS is a classic British scrambler that comes from the heyday of AJS motorcycles, renowned for their rugged performance and competitive edge in off-road and scrambling events. The "CS" in the model designation stands for "Competition Scrambler," indicating that this bike was specifically built for off-road competition.

It features a 498cc single-cylinder engine, offering robust torque and a relatively light frame that was ideal for challenging terrains like dirt tracks and rough countryside. The AJS 18CS gained a strong reputation in the 1950s for its performance in trials and scrambles. It uses a high-compression engine combined with an alloy cylinder head, giving it both durability and power. It was popular in the motocross and desert racing scene, especially in places like Southern California. In this video you can see a demonstration of the old-school procedure required to get these classic machines running.

Here's what happens during a cold start. The fuel tap (petcock) is turned on to allow fuel to flow from the tank to the carburetor. Old motorcycles like the AJS 18CS often need the carburetor to be "tickled." This involves pushing a small plunger or button to flood the carburetor with fuel, making it easier to start the engine. The choke is set to limit the airflow and create a richer fuel mixture, which is necessary for a cold start. These vintage bikes rely on a kickstart system. The rider positions the kickstart lever and gives it a firm kick to turn the engine over. With no electric starters, the rider may first bring the engine to the compression stroke manually to ensure maximum efficiency during the kickstart. Once the engine fires up, there's the unmistakable sound of the British single-cylinder engine coming to life, with a throaty, low-pitched exhaust note that vintage AJS motorcycles are known for. After the bike starts, the choke may be gradually opened, and the engine idle speed adjusted to run smoothly as it warms up.

The cold start procedure on an AJS 18CS is part of the charm for vintage motorcycle enthusiasts. It shows off the mechanical simplicity yet reliability of this legendary motorcycle. The experience of starting one up brings back memories of a time when machines were built to last and relied more on the rider's knowledge and touch. Watch the video below and listen to how perfect the motorcycle's engine sounds.