Show I TESTING FUEL SYSTEM AND ADJUSTING I CARBURETOR IN OPERATING AN ENGINE IW I Ij v i x x 1 f. f r j A Gasoline Engine Furnishing Power to Pump Water Prepared t y tho lie United States Department Department Department Depart Depart- ment of or Agriculture When an examination has shown that lint a good spark sparl Is being obtained at atthe atthe the right time the lie next step Is to see whether the engine is receiving the lie proper mixture of fuel and air all Many carburetors are arc made so that It is easy to remove the lie cover and see whether there here is gasoline In the bowl and where this Is possible It is the easiest wa way to determine whether the fuel Cuel supply is all aH right up p to that point Other types of carbur carburetor tor have tight covers but are arc equipped with small s-by s opening Which one can determine de de- de- de ermine termine whether a supply of fuel Is available If It there Is no fuel in the carburetor either the tank is empty empt or there Is some sonic obstruction in the pipe line between between be be- tween the tank and the carburetor Water in Gasoline System To see that the lie carburetor contains a n liquid which looks s' s like gasoline however is not enough as water and gasoline look very ver much um alike e and It is not at all aH uncommon for water to be bo present in Ia the lie gasoline s system stem Neither Neith Neith- er docs this wat water r always enter the thes s system when it is being filled fined us as Is generally supposed It is often the lie result result re re- re- re sult suIt of condensation of moisture on the sides of the lie gasoline tank which runs funs down and settles at the lie lowest points in the s system stem This may be in the bottom of the thc carburetor In the supply pipe or in the lie strainer or settling chamber Where strainers or or settling chambers are provided these should he le drained and cleaned frequently especially especially es es- es- es In cold weather when any water water water wa wa- wa- wa ter present may cause considerable trouble by freezing For Removing Water A petcock on the carburetor is a good means for Cor removing any water which ma may have settled at the thc bottom of th the the- bowl jowl of the carburetor and which when present will cause difficulty In starting When making a test in this wily way it Is usually advisable to allow enough gasoline to run through to tomake tomake tomake make sure that the carburetor has a n full fun supply as sometimes a n partial stoppage of the pipe will allow aHoa a small amount of gasoline to get by Into the carburetor but not enough to aU allow ow the engine to start easily Allowing a n half-cupful half of fuel to run through it eliminates this possibility It is easy to ascertain whether water is present in the lie carburetor by catching In a glass bottle or tumbler the liquid which runs through when the petcock is open Any water vater present will settle at the bottom of the the- glass and a thin line will be visible between the water and tho the gasoline Air Is Important It is not enough merely to have fuel fuelIn fuelin fuelin in the carburetor it must be mixed with the proper amount of air as ItIs it itIs itIs Is drawn into the combustion chamber It sometimes happens that lint the tile needle I valve is closed or ol stopped with dirt and that while there Is fuel in the tile carburetor carburetor carburetor car car- none can cnn get Into the comb combus combustion s- s tion chamber If the engine has a pet- pet ock Sock leading Into the combustion chamber by opening this and crankIng crankIng crank crank- Ing the engine a a few times Umes one can tell by smelling the escaping air whether gasoline is entering the cham thorn ber her The same sonic result can cnn be obtained by smelling the exhaust when the engine engine engino en en- gine gino is turned over or b by removing a spark plug closing the hole during the suction stroke e and opening It during dur dur- ing lag the compression stroke j dU-j Make Engine Start By alternately opening and closing the needle valve alye first being careful to note the lie original position so that it will willbe be possible to readjust it If necessary it Is easy to see whether a different mixture will make the lie engine start Or when there Is doubt whether enough h fuel Is entering the c cylinder a asmaH small quantity of gasoline about a teaspoonful may be poured into the combustion chamber through the priming prim prIm- lag ing cock or spark-plug spark hole holc and allowed allow allow- ed to stand for a minute or two to vaporize and mix with the lie air all before cranking the engine If then one or two explosions occur and no more it Isan is isan an nn indication that lint only the priming has hns burned and that fuel is not bein being furnished furnished fur- fur In sufficient quantity through the carburetor Mixture Too Rich It sometimes happens that too loo rich a mixture of fuel and air all enters the combustion chamber which is practically practically cally as ns bad as no at ut all as the rich mixture cannot be exploded by bythe bythe bythe the spark This does not often happen with a cold engine and with the lie grades of fuel now on the lie market but it is not at all aU uncommon with a warm en en- gine There are several everal ways of overcoming overcoming overcoming over over- coming this Closing the needle valve an and cranking ci the engine a few times will wiH remove the rich mixture mixture mix mix- ture nrc quickly and replace It with pm pra pra- pra pure air ah Removing a spark plug or opening a petcock leading into the lie combustion chamber and then cranking the lie engine slowly a few t times may answer the lie purpose al although although although al- al though as long as ns the needle valve is open some fuel will continue to to tobe be drawn into the cylinders Testing the Compression It seldom happens that lint the lie compression compression compression compres compres- sion of an engine suddenly becomes s so so poor through ordinary wear as to tomake tomake tomake make it impossible to start with the lie methods commonly used An open valve however will wiH bring about this result Anyone who has ever eyer started a gasoline engine when it was in good working order should be able to tell at once whether the compression is entirely entirely entirely en en- gone as soon as he lie undertakes to crank the engine When compression compression compression compres compres- sion suddenly fails falls it is probable that the trouble is due to leaky lealy piston rings or v valves and the remedy is usually obvious obvious ob ob- ob- ob when once the lie cause Is located The Time hiss made by ly the escaping air durIng during during dur dur- ing the lie compression stroke is often enough to indicate the plate where It ItIs itis' itis Is is' escaping s' s ng |