Fixing issues with pit bikes for beginners and pros without the stress
Pit bikes are fun to ride, and the fun lasts as long as the bike is peak performing. Nothing frustrates a Motosport rider than a bike that refuses to start or one that slows down. These bikes are made for speed and action, and a problem bike offers neither. As a biker, you should possess basic to moderate skills in troubleshooting. Fixing issues with pit bikes is no big deal once you get round to understanding the bike architecture.
If you have tried everything to start a bike that won’t start and still the problem persists, it’s time to turn your attention to the engine. A worn-out engine can cause problems starting the bike. Low compression is one of the most common problems in pit bikes that have been used for years. Engine compression reading at the start when the engine was new determines the compression drop. If the compression has reduced below 25%, the engine needs rebuilding.
A worn top-end is the main reason for low compression in a 2-stroke dirt bike engine. Generally, a top-end rebuild is replacing the piston and/or just the piston rings. The cylinder should be re-honed or re-plated if it is worn out or scratched. A 4-stroke top-end rebuild includes new valves and valve seals with a new timing chain.
The filter allows clean air into the engine while filtering harmful dirt and debris. A dirty air filter impedes the airflow causing the engine to burn too much fuel. A clogged air filter also results in a rich fuel setting, hard starts, engine stalling, black smoke from the exhaust, and a sluggish throttle. Cleaning the air filter or replacing it usually solves this problem.
A dirty or incorrectly jetted carburettor causes bogging, which is the bike’s hesitance to accelerate. When a bike sits for weeks with fuel in it, the pilot jet circuit gets clogged. Proper float height is crucial before changing any jets. Ensure that the float and needle are working properly and not sticking. Learning to jet your carb or tune the fuel injection is a useful skill.
When your pit bike is not idling, one reason is idle screw set too low. Turn in the screw on the carb or throttle body clockwise to bring the idle RPM up enough so that it won’t stall. Older air-cooled pit bikes need higher idle when cold. You can turn the idle down as the engine starts to warm up. Turning the air screw out on a 2-stroke carb gives the air/fuel mixture more air to make it leaner. Turning the fuel screw out on a 4-stroke carb gives it more gas, making the mixture richer.
Malfunctioned carburettor springs prevent the throttle valve slide from opening during acceleration to let air in. With a lack of enough air, your bike will lose power. Carb springs are located where the throttle cable comes into contact with the carburettor. Remove all pod filters to see the interior of the carburettor. Inspect the reaction of the butterfly valve each time you twist the throttle. The problem lies where you don't see valve movement.
Problems with spark plugs
Fouled spark plugs cause the engine to misfire. It might be an intermittent or constant problem when you try to accelerate. Cleaning a fouled spark plus is a very temporary measure. Replace it altogether.
Clutch slipping, clutch dragging, a notchy clutch, and a stiff clutch are the most common clutch problems in a dirt bike. For a smooth and light pulling clutch lever, regularly lubricate the clutch cable. Adding a different leverage point on the clutch lever can increase the leverage, making it easier to pull in the clutch. Make sure you do this only after lubricating and/or replacing your clutch cable.
Becoming familiar with the inner architecture and system functions of your pit bike enables you to be a proficient rider. And, it helps you prevent damages to the bike. Buy the latest pit bikes from Mini Bikes Off Road.