2 Stroke Racing

In the UK, karting is divided into two main categories, which are known as 4-stroke racing and 2-stroke racing. Most of the karting classes in the UK fall into either of these categories. This article concentrates predominantly on 2-stroke racing, but we have a separate article on '4-stroke racing', if you want to read more about that aspect of karting.

What is 2-stroke Kart Racing?

2-stroke kart engines were originally used in motorcycles, but this is no longer particularly the case, as they are now created by specific kart engine manufacturers like Comer, TM, Yamaha and Rotax. 2-stroke kart engines can range from 4 hp (horsepower) to 7 hp, depending on the power of the engine. For example, a Formula A kart with a 100cc 2-stroke engine can generally go from 0 to 60 mph (miles per hour) in less than five seconds, and can reach 85 mph as a maximum speed. A single cylinder 60cc engine tends to have between 4 and 7 hp, while a much more powerful twin 250cc engine can reach 90 hp. 100cc 2-stroke kart engines can run up to 19,000 rmp (revs per minute). Most modern kart engines are water-cooled, in sharp contrast to the air-cooled varieties that were used in the sport. 4-stroke kart engines are usually air-cooled.

Which Karting Classes Use Karts with 2-stroke Engines?

There are several karting classes in the UK that use karts with 2-stroke engines. Some of these are briefly discussed in this section (you can read our 'Junior Karting Classes' and 'Senior Karting Classes' articles to see more information about many UK karting classes):

• Comer Cadet: This karting class is part of the Cadet class of kart racing and is aimed at children aged eight to twelve. The karts in this class use 60cc Comer 2-stroke engines.
• Rotax Max 125: This karting class is part of the Senior class of karting, which all karters are classed as being part of once they have turned sixteen. The karts in this class use Rotax FR125 Max sealed 2-stroke engines with clutch.
• ICA (Intercontinental): This karting class is part of the Senior class of karting, which any karter can become part of after the age of sixteen. The karts in this class use reed valve 2-stroke engines (karts with 100cc engines are the most powerful that are allowed to take part in this karting class).
• 210 Gearbox: This karting class is part of the Gearbox class of karting. The karts in this class use Villiers 9E air-cooled 2-stroke engines (or replicas of this type of engines). As with all other senior karting classes in the UK, karters in this class are all aged over sixteen.

Petrol Engines

If your kart uses a 2-stroke petrol engine, it will require more maintenance. They have to be completely stripped down after 35 hours of karting, and this must be done by a professional. If you don't own your own kart and are reliant on those owned by a karting track, this won't be a problem as you won't need to take on maintenance costs and duties.

2-stroke karting is an important part of karting for most go-kart drivers, as many of the karting classes in the UK uses karts with these engines.