When the gasoline engine is started manually, the rebound is very intense, because the valve clearance of the gasoline engine is too large, so it is over-compressed, and the ignition time is misplaced, resulting in late ignition. If it can't start smoothly, it will rebound, which can be solved by reducing the valve clearance. The specific operation steps are as follows:

1. Pull off the high-pressure cover of the gasoline engine.

2. Remove the valve cover fixing screw.

3. Remove the valve cover.

4. Turn the crankshaft to the top dead center.

5. Use two round-headed wrenches to adjust the valve clearance.

The gasoline engine is characterized by high speed, simple structure, light weight, stable operation and convenient use and maintenance. Gasoline engines are widely used in automobiles, especially small cars.