How to adjust valve clearance on a scooter?

Many owners of scooters with four-strokeengines know that valve clearances need to be adjusted. But due to inexperience and ignorance, they do not pay the necessary attention to this procedure. And in vain. By adjusting the valves on your engine, you will not only improve the stability of its operation, but also extend the service life. It may seem that a few millimeters do not greatly affect the operation of the scooter.

Однако практика показывает, что слишком маленькие or too large valve clearances accelerate the wear of engine parts by several times, helping to reduce the time of its operation by several times. Let's answer the question of why this is happening.

Valve clearances forscooters (engine capacity 50-100 cm3) about 0.05 mm. This value is the same for both the exhaust and the intake valve. However, if it is increased, then the engine starts to knock. At the hearing when the engine is idling, this engine operation can be heard as a sewing machine tarahtenie.

But the trouble is not that.Increased thermal clearances of the valves shift the valve timing. Therefore, when adding engine revs, the scooter’s thrust decreases, fuel consumption and valve mechanism wear increase.

When valve clearances are greater than necessary, thenthe engine is in even worse condition. After all, there is a loss of compression from the fact that the gaps, heating up, become even smaller, opening up the valves. Gas breakthrough and power loss occur. There may also be a burn through of the valve or its seat.

After this trouble, the scooter generally stopsmove well. His power is lost and the candles turn black from soot. Therefore, there is nothing left to do, how to replace valves or even the entire head.

It is better to adjust the valve gaps on a scooter once a thousand kilometers than to buy new parts. To do this (for example, for Alpha and Delta), we need the following tools:

- keys set;

- a set of probes;

- pliers.

But do not forget that the valves are adjusted when the engine is cold (when the air temperature is below zero, then it is slightly warmed up). The process of work is reduced to the following operations:

- Twisting the candle.

- Installing the piston at TDC (end of compression stroke),freeing up the valves. To check this, it is necessary to unscrew the cap on the crankcase lid and, turning the crankshaft, to ensure that the mark "T" was exactly in the middle of the hatch. Using the key, unscrew the cap and, turning the screw on the yoke, make the adjustment. This operation must be done carefully so as not to damage the screw, which is often plastic. Measure the probe gap, which with a thickness of 0.04 mm should be free, but with 0.06, do not prolazit. The gauge to 0.05 mm should enter with difficulty.

- Tighten all the plugs and candles back into place.

That's all. As you can see, there are no special secrets here.Now you can start and warm up the engine. With proper adjustment, you immediately determine by ear how quieter your scooter began to work and how pleasant it is to ride it.