Get To Know Your Mini Moto – Part II
The second part of Get To Know Your Mini Moto will delve further into the many components that contribute to a mini moto, namely the clutch and spark plug, and explain how each plays its part in these remarkable machines.
The mini moto uses a centrifugal clutch to power the drive the sprocket, which in turn drives the back wheel of your mini moto.
When you start your mini moto the clutch spins as the engine ticks over. The clutch is engaged when you pull back on the throttle. The increase in speed of revolution of the clutch makes the clutch expand and grip the inside of the clutch bell which turns the sprocket that drives the back wheel of your pocket bike.
The clutch can be set up in different ways depending on the type of performance that you want from your minimoto. Adjustable clutches are not standard on mini moto’s but an after market Polani or Blata style adjustable clutch can be used in your new mini moto. These allow the rider to adjust the mini moto’s set up in according to their preference. Setting the clutch to engage too late when the engine has built up too much power may cause the clutch to slip and never fully engage. This can result in excessive wearing. However setting the clutch to engage too early, before the power has built up in the engine can cause your pocket bike to ‘bog down’, resulting in slow acceleration. The perfect set up is to get the clutch to engage just as the engine has built enough power to rocket the mini moto away, but without making the clutch slip, this is achievable through trial and error.
Making sure that your spark plug is fresh is important in a two stroke mini moto engine. You can tell a lot from the color of the spark plug. The top part of your spark plug is covered in ceramic insulator which, when brand new is white. This part of the spark plug can change color according to how your engine is running. The plug should appear as a nice tan color when the engine is running perfectly, this indicates complete combustion. A grayish or white color indicates that the engine is running too lean which can result in engine damage. In this case you should clean and check your fuel system for any obstruction, check your fuel mixture, check for loose intake manifold bolts and carburetor mounting leeks, faulty gaskets and leaking crank seals. Anywhere that your engine could potentially leek and suck in fresh air can be the source of a lean condition.
A blackened or oily spark plug indicates improper combustion and is the result of running too rich. This can be caused by too much oil in the mixture or the spark plug could be faulty and misfiring. Check the fuel mixture and replace the spark plug.