Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/126458
o orcyc e nu s o 00 0) ~ 1- ~ By Ray Hill If you answer all the questions correctly, join Erv Kanemoto, Bill Wemer, t'lS CaTTUthersfor a beer and swapttm,ing secrets. ~ If you answer some of the quest'ions incorrectly, have a beer and Erv, Kel, Bill an ~ later. ' If you answer all the questions wrong, callJunior Samples at BR 549. He has so wrenchesfor sale at a price you can't refuse. men I. A lpark plug's heat range to: A. The diltance heat radiatel from the spark into the Iquish area. B. The hottest and coldest tem· peratura the plUl('s porcelain in· lUiator can ltand before It craw. C. The plug's ability to transfer beat. D. The temperature at which the spark plug will no longer permit a spark to jump the gap between its elec· trodes. Z. In addition to its lubricating duties in a four«roke engine, oil aIIo sena a cooling function. A. True. B. False. C. Neither of the above. l!. A~d piMon means that: A. The stone \lied to grind the piston is cam·shaped. B. The piston is no good. C. The piston is slightly oval· shaped. D. The piston is shaped like a cam· lbaftlobe. E. A guy named Cam made the piston. 4. A tat light can be uecI: A. To determine if your sweethean really cares. B. AI a dan when things get dull in the pits. C. To determine if current is reaching a headlight that won't bum. D. To determine if wheel alignment is spot on. E. To mea.sure the exact voltage in an electrical circuit. 5. You decide to check the ignition tiDaing ou your truMy two«roke twin. It's running oby. But a little maiDteDaIlCC can't hun anything. Besides, YOU'ft af beer and ha"e nothing die to The engine's. two crankshaft throws aft 180 c1qpea apan. When ODe piMon is firing at about TDC (Top Dead Center), the other oue is near BDC ( ~ Dead Center). The bike has a battery-anckoil ignition letUp, and two lets of breaker points. As you break out your obm_r and. dial indicator, you suddenly realize that you know the tim.ing spea, but you don't know which let of points belongs to which cylinder. Of the choica giftD below, which is the euiest way to cIetennine which cylinder each let of breaker points belougs to? , A. Call RUSI ~ . B. Remove the heads and crank the engine over by hand. When one piston is at TDC. see which set of points is open. That set of points belongs to the p~onatTDC. C. Do the above. but see which set of points is closed. That let belongs to the piston at TDC. D. Tum the ignition switch to the run position. Make sure the kill switch is in the run position. Connect one of the spark plugs to its spark plug cable, and ray the plug against a cylinder fin 10 that the threads are touching the fin (or other &Q!iII!I ,pund). Rotate the cr in the direction it turns when the engine is running. When you see a spark jump the spark plug's electrode gap. stop turning the crankshaft. Look at the points and see which set is open. The open set belongs to the cylinder of the spark plug that just fired. E. Everything in answer C is right, except that the set of points that is closed belongs to the spark plug that just fired. F. None of the ahove. 6. A buzz box is u.ed to: A. Locate unusual noises m a motorcycle engine. B. CaB room service. C. Aid in checking ignition timing. D. Del.I: uine e cause of excessive vibration in the primary drive unit. E. Keep you awake on those long lonely rides down the interstates. 7. The pu~ of a rectifier is: A. To conven alternating current into direct current. B. To conven direct current into alternating current. . C. To determine if current is reaching the stator. D. To change three·phase alter· nating current into double· phase direct current. E. None of the above. 8. When inatalling a new let of rings, a cylinder hone is uecI to: A. Break the glaze on the cylinder wall 10 that the rings will seal properly. B. Enlarge the bore slightly so the engine will run faster. C. Neither of the above. 9. Of the choices gi"en below, the bat oil to use in your four-ltl'Oke _is: A. Oil with an SA rating and of the viscosity recommended in your owner's manual. B. Oil with an SE rating and of the viscosity recommended in your owner's manual. C. Oil with a PI rating and of the viscosity recommended in your owner's manual. 10. Reed Valves are opened and closed by: A. A dashpot. B. The crankcase. Drawing for answer 14. 01_ Vocuum_ DrlIwlng for answer 1. to top side ~Q::sJ'itt.. Jol_ - ...... ,-. .Al<----+-~ - -t-4I-L ----I;;::-4-r-' COlO -jot HOT When throttle valve ia opened, VllCUum trevets through the vacwm peaage to the diaphrll9m lIbove the throtlle slide, C8U8ing the slide to lift. This in lU'n lifts the jet needle. allowing more ga to be drawn up from the Ilo8t bowl.