See that the valves are properly timed: Read very carefully paragraph on Valve Timing (page 17).

See that the magneto furnishes a spark and that it takes place just as the word 'spark" passes the top edge of the valve rod as shown in Fig. 15, page 50.

The butterfly valve in air damper cage and the governor shaft arm should be properly adjusted. (See last paragraph on page 6.)

FUEL, CLEAN CONNECTIONS

Make certain there is plenty of fuel in tank.

See if the fuel flows to the mixing valve. Dirt sometimes gets into fuel pipe and collects on the fuel valve or under the check valve. Clean all connections carefully.

If you find the mixing valve or connections are dirty, drain the tank by removing the plug and strain the fuel through a chamois skin, which will keep out the dirt and water.

WATER IN FUEL

Water in fuel will cause loss of power. The presence of water is rather hard to detect, but if doubtful you can make certain by straining the fuel through a chamois skin. This is rather dangerous, however, as the gasoline, being a volatile substance, in passing through the chamois forms static-electricity, which will cause spark unless the funnel fits securely on a conducting material which is properly grounded; in other words, if the funnel fits securely on the mouth of the tank which is properly grounded on engine, you will need fear no danger from this source.

TOO MUCH FUEL

It is a common mistake to flood the cylinder in starting engine. which makes it very hard to start. Unless engine is subjected to a low temperature, do not flood the cylinder, as engine can he choked down by feeding too much fuel just as easily as by not feeding enough. If fuel is subjected to low temperature, the rate of vaporization is much lower and an extra amount of fuel is necessary.

TOO LITTLE FUEL

If engine is not given the proper amount of fuel there will he a popping and back-firing out of air inlet; however, this popping noise is also caused by poor ignition, valves not seating properly, or poor mixture. It is possible that the head gasket has given out, allowing water to leak out and mix with the fuel; if so, it will be necessary to replace with a new gasket. Generally, the leak is so slight that after engine has once been started the leak is not noticeable.