MSD Tech Line - MSD Powersports

Plug Wire TipTo keep your engine’s spark plug wires in tip-topcondition there are a few simple steps you cantake. For starters, applya small amountof MSD Spark Guard,PN 8804, a dielectricgrease, to each wireterminal. This keepsany moisture out ofthe boot while lubricatingand insulatingthe terminal-to-plugconnection. It alsoaids in pulling theplug socket off withouttearing the bootor wire.Extra protectionfrom heat is always agood idea. MSD wireshave a very durable sleeve but in applications withtight engine compartments and close exhaust systems,additional protection is a benefit. MSD offersPro-Heat Sleeve, PN 3411, a silicone coated wovenglass sleeve that slides over your wires for addedprotection. If you’re looking for protection aroundthe boot MSD’s Pro-Boot Guard, PN 3412, is theanswer. This is an extra thick sleeve of woven glasswith a silicone coating and will protect the bootfrom excessive heat.Another important point to consider is the waythe plug wires are routed. Using good wire separatorsis a key in preventing inductive crossfire whichoccurs when two wires that are consecutive in thefiring order are run next to each other. MSD offers avariety of Separators that will help position the wiresaway from exhaust manifolds and sharp edges whilekeeping the engine compartment looking good.www.msdpowersports.comSPARK PLUG WIRES AND SPARK PLUGSSpark PlugChoosing the correct spark plug design and heatrange is important when trying to get all the performancepossible. Since there are so many enginecombinations and manufacturers, MSD cannot recommendwhich plug or what size gap is exactly rightfor your application. It is recommended to followthe engine builder’s or manufacturer’s recommendationsfor plug heat range and gap.Once a proper plug is selected, you can experimentwith the gap to get the best performance. Byusing these recommendations as a starting point,you can experiment by opening the gap in 0.005”increments then test. When the performance fallsoff, the gap is too large. Carbureted or fuel injectionengines can use larger gaps, but turbo or superchargedengines should stick with the smallergap. If no significant gains are achieved, go withthe smaller gap. Remember, the larger gap taxesthe plug, wires, cap and rotor.Rule of Thumb Plug GapCOMPRESSIONGAPUP TO 10.5:1 .040 - .04510.5:1 - 13:1 .032 - .040OVER 13:1 .025 - .032Note: These are recommended for normallyaspirated engines only. Reduce the gap for blower,turbo or nitrous applications.After changing the gap,reading the spark plugs isa helpful tool in gettingthe right tune up. Theair/fuel ratio and howit’s burning can be readon the ceramic portionof the spark plug. A ringcan be seen where theeffective heat transfertakes place. The closerthis ring is to the tip, thericher the mixture. Closerto the base of the plugmeans the engine is runningmore lean.MSD POWERSPORTS • 1490 Henry Brennan DR., El Paso, Texas 79936 • (915) 858-3365 • FAX (915) 858-3496