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How to Adjust the Motorcycle Engine Valve?

Nov. 09, 2020

Whether a motorcycle engine has a starter lever does not seem to be related to the valve adjustment. Of course, if there is a starter lever, it is relatively easy to find the top dead center. However, according to the professional valve clearance adjustment operation process, the starter lever plays a role in this process. The effect is not great. Today, the engine valve exporter will show you how to adjust the valve on a motorcycle without a start rod

Motorcycle engine valve clearance is a normal working clearance reserved at the beginning of engine design. The existence of this clearance is mainly to consider the problem of valve closure, because the temperature of the cylinder head of the engine will be relatively high, and changes with temperature If there is no gap between the valve and the rocker arm, then as the engine temperature increases, valve leakage will easily occur, so valve clearance is very important.

However, as the service life increases and internal parts wear normally, the valve clearance reserved at the beginning of the design will change. The most common phenomenon is abnormal noise. At this time, we need to adjust it. In the process of adjustment, it is necessary to find the top dead center.

Motorcycle Engine Valve

The so-called top dead center of the engine is the position where the piston is at the highest point of the cylinder. When the piston reaches this position, the valve will just be in the closed state, and there will be a gap between the camshaft and the rocker arm, and the valve. At this time, the valve is adjusted. The best time point for the gap.

Under normal circumstances, some old drivers will use the start lever to turn the engine to swing the rocker arm in order to quickly adjust the valve clearance to find the position of the upper point, but in fact, the so-called top dead center will deviate in many cases.

The correct operation is to open the observation window on the cover of the magneto, use a wrench to turn the magneto rotor to observe the "T" position on the rotor. When the magneto rotor is in this position, the piston will reach the top dead center extremely accurately. The four-stroke engine crankshaft completes a work cycle every time it rotates twice. It is also necessary to swing the rocker arm according to the gap size to determine whether it is the top dead center for adjusting the valve gap. If it does not rotate for one revolution, the top dead center will appear.

It can be seen that in the process of adjusting the valve clearance of the motorcycle engine, whether there is a starter rod or not has little effect. We can completely adjust the valve clearance of the current engine through the observation window on the magneto cover, but there is no observation window. Remove the magneto cover, you can also find the top dead center.