Yamaha RX10RX Owner's Manual

Contents

Periodic maintenance• Keep your body and clothing away fromrotating parts when servicing the snow-mobile with the shroud or covers re-moved.• Do not touch the hot muffler and engineduring or immediately after operation.Specified spark plug:Manufacturer:NGKModel:CR9EBSpark plugs are produced in several differentECS00370CAUTION:Make sure that all cables, leads, etc., arerouted properly before installing theshroud and covers.thread lengths. The thread length or reach isthe distance from the spark plug gasket seatto the end of the threaded portion. If the reachis too long, overheating and engine damagemay result. If the reach is too short, spark plugfouling and poor performance may result. Al-so, if the reach is too short, carbon will form onNOTE:When installing the shroud and covers, besure to tighten the fasteners and the top coverbolts securely.the exposed threads resulting in combustionchamber hot spots and thread damage. Al-ways use a spark plug with the specifiedreach.ESU11780Checking the spark plugsThe spark plug is an important engine compo-nent and is easy to inspect. The condition ofthe spark plug can indicate the condition ofthe engine.Check the coloration on the white porcelaininsulator around the center electrode. Theideal coloration at this point is a medium to alight tan color for a snowmobile that is beingridden normally. If a spark plug shows a dis-tinctly different color, there could be some-thing wrong with the engine. For example, avery white center electrode porcelain colorcould indicate an intake track air leak or car-buretion problem for that cylinder. Do not at-tempt to diagnose such problems yourself.Instead, take the snowmobile to a Yamahadealer for inspection and possible repairs.You should periodically remove and inspectthe spark plug because heat and deposits willcause a spark plug to slowly break down anderode. Consult a Yamaha dealer beforechanging to a different type of spark plug.Spark plug reach:19.0 mm (0.75 in)1 . Spark plug gap2. Spark plug reachBefore installing any spark plug, measure theelectrode gap with a wire thickness gaugeand adjust to specification.Spark plug gap:0.7–0.8 mm (0.028–0.031 in)47