A go cart is typically a small, motorized vehicle used by anyone from children for fun, to adults who race specialized go carts on sanctioned race tracks. Of course, if you have one of these vehicles, then you know the most important part besides you the driver is the go cart engine to go with it.
For a kids go cart, they may use basically a lawn mower engine, that is totally stock, or to say it is just the way that the manufacturer built it. Some of the common manufacturers of these cart engines are Briggs and Stratton, Kohler, Tecumseh, Robin and Honda. We will take a look at all of these kart engine builders and highlight their specs.
First Manufactured Go Cart Engine
The very first go kart engine was manufactured by a company called Mcculloch in 1959. Its first model was known as the MC-10 which was nothing more than a 2-stroke chainsaw engine. It was later in the 1960′s that motorcycle engines were modified to be used in karts.
The basic lawn mower engine go carts type is usually between three and ten horsepower, but may be as large as 20hp.
Many of the most basic motors are called “industrial flat head” engines. In a typical modern automotive engine, the valves are in the head, which bolts to the top of the cylinder block. This is called an overhead valve engine.
The valves allow the fuel/air mixture to enter the cylinder for combustion, being drawn in by the downward stroke of the piston. The exhaust gases leave the cylinder, as they are forced out by the piston. The valves are opened and closed by a camshaft, which can either be in the engine block, or in the head, depending on the design. The overhead valve engine is becoming more common in the small engine world as well.
Flat head engines are a relatively old design, and they were used in cars for years. In the flat head design, the valves are in the engine block or cylinder itself. The head of the engine is a cover, or a cap as it were, to house the combustion chamber. Many of these look like a flat piece of steel, hence the name, “flat head.”
Note that these are all conventional four stroke go carts engines designs that I refer to. Some go kart engines are of a two stroke design. In a four stroke, the piston completes two upward strokes, and two downward strokes, in a complete combustion cycle. A two stroke engine only completes one upward, and one downward stroke.
Mechanically, there are some differences as well. Two stroke engines do not have valves… they use a system of ports that are covered and uncovered by the piston to introduce fuel/air and expel exhaust. Two stokes also generally use a gas and oil mixture, and do not store oil in the engine for lubrication.
Basic go cart engine parts and motors can be purchased from small engine shops, as well as online from websites. Lawnmower shops also carry lawnmower engine parts. If you are into racing, there is an entire industry of go cart racing engine builders who will create a super high powered engine for you. Just make sure that you bring your checkbook.
Engine Types
* Electric go carts which run on rechargeable lead acid batteries or hydrogen fuel cells are popular because they are environmentally friendly and less costly. Electric carts do not release any pollutants to the environment. Race tracks for this type of engine can be installed indoor as a result of the exhaust free machine. A fully charged go-kart can usually run up to 120 minutes before its level of performance declines.
4 Stroke Engine
* 4-stroke go cart engines power range from approximately 5 to 20 hp. Companies like Briggs & Stratton, Robin, Kohler and Honda manufacture these types of engines which are often used for racing and fun kart applications. Also, other companies like Yamaha and TKM have developed engines which are made specifically for carting at 15 to 48 hp.
2 Stroke Engine
* 2-stroke engines are developed by companies like Comer, IAME, TM, TKM, WTP, TItan, Yamaha, Rotax and Vortex to name a few. These types of engines are made from an 8 hp single cylinder 60 cc units to 90 hp for twin 250 cc units. Most popular sub-categories of these engines include the Touch and Go (TAG) 125 cc units.
Transmission
Karts do not have a differential only a chassis or a frame that is designed to make up for the lack of the former. The latter’s design permits one of the rear tires to slide or to lift off the ground when getting on sharp corners. Chain or belt allows power transmission from the rear axle to the engine. Engine and axle ratio are removable thus they can be configured to suit the type of track thereby ensuring optimum performance from your kart’s engines. I bring this up because the transmission and engine go hand in hand and work together for performance.
Data Acquisition Systems
Latest models of go karts are equipped with data acquisition systems which show via the monitor different parameters such as timing of laps, number of laps, best lap, speed and even lateral and longitudinal acceleration, steering wheel position and brake pressure. These data are also recorded and can be made available for analysis using software.
Understanding the dynamics on the making of your go cart engine and where most of its power emanates from, is just half of the game however, you are now ready for the race of your life.
