Show TEST OF IGNITION SYSTEM IS IMPORTANT IN LOCATING GASOLINE ENGINE TROUBLE ilk V tractors Tra etora are ara coming into use on many farms which emphasizes the importance por lanco of knowing how to run a gasoline engine prepared Pre parea by the united states department ot of agriculture with till nil engines using spark plugs it Is coin ivel y easy to ascertain whether the lie ignition system Is working properly simply remove a plug and uncertain ascertain that hint tho porcelain or other material on tho the inside of the plug Is not coated with ind and that the points tire prop properly cily spaced ono one thirty second of tin nn inch is about the right space for most systems chero a dry battery Is used this Is nebout equal to the alio thickness of it a worn dime A wider gap will viii often ninke make starting difficult especially when tile ephre Is rather weak or where a high tension magneto Is used in the latter case tile tho best results will often bo be obtained when the gup gap la Is not more than fihnn one fortieth or even ono one fiftieth of tin nn inch then reattach attach re the lie wire annil lay the he plug so that the metal base touches tile tho engine engino ens casting ling while the ilia end or of tile wiro wire and tho the metal tip of tho the plug are lit at least half nn an P inch from any metal part connected with the engine and in such it post tion that the points are while cranking the he engine then turn tho the engine over a few times at least ns as ranny many times limes is as there tire arc cylinders and note whether a spark jumps across the space between tho ho points it la Is not sufficient clent however merely to ascertain it if there la Is it spark it must lie hot enough to ire fire the compressed charge in the cylinder it if Is of course difficult to tell by merely looking nt at it whether tile the spark la Is hot enough or not but if it Is a heavy blue or a i bluish white or a tat fat yellow one looking like a small flame it Is probably till nil rl right glit if very thin and greenish or showing red the chances tire it Is too weak to fire alro tile charge one rony familiarize himself with tho the ns as hect of a good spark ns as follows finding a good spark while the iho motor la ili in satisfactory 6 running condition loosen tho the nut on the top of the plug while the engine Is stopped so it will bo be easy to remove the wire from the plug after tile engino engine Is started then start the engine and by taking hold of the wire where it Is covered with insulation move the end of the wire very slowly awny from the center of the plug rind watch tile spark jump closely observing its color and thickness it Is tilso also weli to noto note the distance the spark will jump yet not advisable to force it to jump too great a gnp gap nor should the end ot or the wire bo be el at lowed to rest in if n position where the spark bpark cannot jump to tile the plug or the engine while tile entine engine Is running ns as this tends to break down tile the insulation of the poll in tile the case of high tension magnetos there Is no dang danger r in this respect ns they are fitted with it a safety spark rap gap which tile spark will jump it if for any reason the circuit Is broken elsewhere knowledge of just liow how much of n bpark spar k we tine should obtain with each und kind oy of ignition system la Is frequently of great value in locating trouble and everyone who operates it a gns agns engine should make the above described tests while tile the engine Is in good order it one Is not sufficiently familiar with the looks looka of a good spark to tell by more abs observation erv atlon whether it Is hot enough a i rough test may bo be made ns as follows place a till thin piece of dry cardboard such as an ordinary visiting cord card or three or fr four of dry newspaper between tho points of the plug while it Is lying on oil the engine in the position first mentioned then crank tile engine A good spark sp ark will jump through these leaving it a tiny hole A shark which will not do this ili IB too weak to jump the spark gnp in the cylinder under compression if the engine Is equipped with it ii make and brenk brcak ignition system in which an igniter block Is used instead of a spark plug ping it can bo be ascertained easily whether tile the entire system with tile tho exception of the igniter block Is in good shape by disconnecting the wire from froin the igniter block and snapping it across the corner of tile tho en gine casting or the end of tile tho other wire leading from the coll hut but even though this his gives it good spark it does not necessarily mean that the spark Is given in the cylinder when the engine Is tarold over it may lo be 10 that the points of the electrodes inside the cylinder to do not touch each other when they should or are not making ft a good contact because carbon oil dirt etc have accumulated bet between lyeen these points therefore it if n good spark occurs when the wire Is snapped across part of tile engine crank the engine 0 until tho the movable electrode la 19 released prid allowed to fly back contact riot not being made it if one ne Is not mot sure just when the point of the electrode should be touching the lie engine may lip ito cranked very lowly for two full the end cl of the wire la Is snapped napped across its ita connert connect connection lihi in ow on dio 5 A electrode it no spark can bo be obtained at any position of the electrode it Is evident lint contact la Is not being mado made by the points inside the calli this la ili in case caiso the other ware wre la 19 grounded directly to the engine sometimes tile other wire Is in fastened to a piece of metal insulated from the engine but which touches tou clies part of the engine for tin on when the spark should occur in tile alio cylinder in this case aso if a spark can call bo be obtained by bringing the ends of the lie two wires into contact it should he bo determined whether tho the insulated piece Is making contact I 1 ct with tho the engine properly it if no spark Is obtained it at ilia plug or igniter block when tested as directed it will of course bo be feces sary rory to look over tho the electrical system in order to ascertain what li 14 wrong tile electrical systems of various engines differ considerably and no nato instruction can bo be given for different makes but some general points will bo be mentioned first of all sea that tho the switch Is in starting position much tania has been iou in thousands of cases canes by trying to st satt tt the engino with the switch off next look over till nil wire connections to sea that they are tight and clean it if the engine starts op on a n battery of try dry CON gee that nil all connections between tile tho cells tire oro tight and that no short circuits are caused by tile the metallic portions of tile cells touching with other oilier or by metal connection with the engine nr by tools lying on tile cells etc tho the small knurled nuts on dry cells frequently hooson from vibration and thus interrupt tile whole ignition system testing battery strength Str enoth it la Is n rood goad thing to keep nn fin ammeter handy for use to lu testing the strength of tho the cells of a battery in testing with nn an ammeter it Is best to discard rill all colls cells that do not test over 12 amperes A now new cell should test between 20 and 80 amperes if no ammeter Is available it crudo crude test can lie be made by striking the end of a wire connected to one end cell of tile a battery against the first connection on tho 06 cell fit at the other end do not keep the wire in contact with tho the cell for more than till nn instant doing so BO will weaken the battory battery but by snapping it quickly across the edge of the knurled nut a fe few w times and noting the sparks one can call ascertain whether tho battery Is producing a good current by Inn making icing tills this test a few times with a battery which Is in ili working condition one can easily learn about how much of a spark should bo be expected oil causes trouble sometimes too much oil will cause canao trouble by accumulating cumulating ne on oil ilia contact points la the breaker box bor it Is in easy to c examine ninino these points and goo it if they have oil on oil them are arc rough or pitted pitied or not opening properly if oily rinse with a little gas allne tind wipe dry it if rough or pitted tho the points should bo be smoothed with a file made especially for this purpose it if such llo file Is not n small knife bindo may be used to remove tho the tiny tips of metal which have formed on oil tho the points mid to round off on tho the burred corners it pays however to keep n suitable file on hand for this work for pitted points tire not uncommon and unless properly y smoothed up tip are to get into bad ninin very quickly A gauge la Is generally furnished by magneto manufacturers rs to it termine determine the proper distance bete between erl tile tha points in ili the open position the moans means of adjusting this distance vary with different makes of but tire usually apparent upon examination tile points should separate about one fiftieth of an inch an ordinary pin la Is about ono one thirty second of nn an inch in diameter and a fairly close estimate may bo be made us its ing tills this fact as a criterion if no gauge Is uVal lable provide waterproof cover it Is important that a waterproof cover be provided for the jho magneto mug neto especially ally in the case of engines used out of doors duch na as gas tractors in order to protect the magneto from moisture ind dut dust as either of 0 these Is likely to cause trouble sooner or later dur ig the past few years manista gas engines have been equipped with low tension oscillating magnetos some of cheso ore are mounted directly on tho the igniter block and it la Is easy easy to io test tho the spark by removing the block and tripping the oscillator with the means provided in other easel cases it Is nece necessary sunry to remove ohp end of the wire attach vil d ito to the igniter block and wipe lV it across a mattil part parl of tile the engine at the same time tripping tile the oscillator it Is ri that tile the end of the wire the metal almost instantly after the he osell anfor Is tripped etli also the tha spark will not occur cicur blittle A lettla practice will make tl this ils teak easy |