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The Mini Moto is a small scale replica of the World Super Bikes used by the likes of Valentino Rossi and ex champion Carl Fogarty. The Mini Moto comes equipped with either a two stroke air or water cooled engine which are, depending on the model, capable of speeds of up to 60Mph. But how much do you know your mini moto? In this part I will underline the finer points of the components that make these speeds possible.

The Two Stroke Engine

The two stroke engine produces more hp per pound than the four stroke engine. The two stroke engine consists of three moving parts, the piston, the rod and the crank. The piston acts as valve that opens and closes the intake and exhaust ports that are located on the walls of the cylinder. Unlike the four stroke engine that fires only every other time of the pistons movement, the two stoke engine fires every time the piston reaches the top of its travel. This means that the time spent generating power is doubled in the two stroke engine than that of the four stroke engine, as there is no engine coasting during passive cycles. This is the main reason that the two stroke engine can rev more highly and produce more power (for its size) that the four stroke.

Fuel

The two stroke engine needs to be run on a mixture of petrol and two stroke oil. This is so that the engine is kept lubricated whilst in use.

99% of all starting problems are caused by fuel problems. These can stem from bad or old fuel and improperly mixed fuel (please see mixing chart). Do not use fuels that contain alcohol, as the can cause you bike to run 'lean'. Be advised some racing fuels contain alcohol and are best avoided... We recommend that you use normal petrol for a garage and quality two stroke oil.

A mixture that is too lean i.e. not enough two stroke oil can damage your mini moto's engine as the moving parts are not properly lubricated. This can cause the engine to seize. However a mixture that is too rich can choke the engine and affect the performance and cause starting problems. You can tell if your mini moto is running too richly by the plumes of white smoke coming out of the exhaust and the lack of performance. A rich mixture (25:1) is needed to lubricate the engine during the 'run in' period; you may experience a lack of performance during this period. The pocket bike may run more slowly and acceleration can be sluggish, however when you change to a mixture of 50:1 you will really notice a difference. The leaner mix ignites in the combustion chamber faster and with a more explosive force than the richer mix. This means higher revs which mean more power and acceleration.

We recommend that a fuel mixture of 25:1 is used to 'run in' you mini moto, and a mixture of 50:1 is used thereafter.

'Running in'

Your mini moto should be 'run in' for the first 3-4 tanks of fuel. During this period we recommend that you use a fuel mixture of 25:1. This means a mixture that is made up of 25 parts petrol to 1 part of two stroke oil. During the 'running in' period be careful to not rev the engine to its maximum as this can damage the engine. The 'running in' period will allow the moving parts to become well oiled and the clutch and brakes to 'bed' themselves in. After you have run the minimoto on this fuel mixture for 3-4 tanks, check the chain and tighten accordingly, check the tire pressure, tighten the bolts on the brakes, forks and wheels. You may also need to readjust the throttle settings to allow for the higher revs that changing to a leaner fuel mix produces. The bike should now be ready for a fuel mixture of 50:1.