HOW TO ADJUST THE BUTTERFLY VALVE ON THE 1 3/4 AND 2 1/2
H. P. KEROSENE ENGINES
Across the face of the butterfly spindle and damper lever No.0167 you will find a line. This line should be parallel with the air damper rod No. 173 or thus when the engine is idle. When the butterfly valve is in this position it is wide open and the governor spindle No. 068-C should just touch the end of set nut No. Y467, see page 34.
HOW TO CHECK UP ON ENGINE TROUBLE
If your engine is not running as it should, look for the trouble in one of the four following places: ignition, rich mixture, lean mixture and timing.
If your engine is not firing regularly and does not develop its rated horse power, first remove the lead wire connecting the spark plug and the magneto, hold the end of the wire about 'A-inch from the plug, turn the engine over a time or two until the magneto trips. If the spark jumps the gap with a good bright spark you will know that your trouble is not caused by the magneto.
You should next examine the spark plug, if the spark is coming through the plug as it should you will know that the trouble is not caused by the magneto unless the spark is occurring too early or too late. For adjusting time of spark, see p age 14 (Faulty Ignition) and Fig. 11, page 31.
If black smoke appears at the exhaust muffler and the exhaust has a muffled sound the mixture is too rich and you are using too much fuel. If you cannot regulate this with the fuel valve by cutting off some of the fuel it will be necessary to loosen the air intake or damper spring by releasing the lock nut and turning the air damper stem, No. 1230-K, Fig. 10, page 31, to the right. This is a very sensitive adjustment and the damper stem should he turned but very little at a time until the desired results are obtained.
If there is a popping sound at the carburetor and engine does not develop its rated horse power the mixture is too lean. Do not try to adjust this by adjusting the carburetor until you have cleaned the fuel pipe and strainer No. 38 and 40. You will find a little valve in the fuel line; be sure that it is working freely. After you have assured yourself that the fuel line is cleared and the engine continues to show signs of lean mixture it will be necessary to adjust the air damper spring by releasing the lock nut and turning the damper stem to the left which will tighten the spring and make the damper disc harder to move thereby causing more fuel and less air to be drawn into the cylinder at each suction stroke of the piston. Be very careful not to make this adjustment too tight or you will flood the engine and make it necessary to make the adjustment all over again.
Do not try to make adjustments on the air damper spring until you have assured yourself that all other parts of the fuel system are properly adjusted.
If the engine starts and runs good on the gasoline you put in the carburetor to start the engine with and fails to run good when you turn on the kerosene, you will find your trouble somewhere between the carburetor and the fuel tank.
TO ADJUST THE SPEED OF THESE ENGINES
Make all speed adjustments with speed change adjusting screw No. Y467, see page 31, Fig. 10. If engine runs too fast loosen lock nut on set screw No. Y467 and turn screw to the right. This shortens the distance between the end of screw and the end of the governor spindle rod causing the governor to close the butter-fly valve and slow down the engine.
To increase the speed of the engine turn the adjusting screw to the left thereby increasing the distance between the screw and the governor spindle.