NGK Spark Plug CMR6H 3365

Product Information

Fouling can occur more easily if the air-fuel mixture is not adjusted to compensate for the altitude. Higher altitude = less air = less fuel. Interference suppression resistance (2) is tuned to STIHL machines for the optimal spark and efficiency. This protects the machine’s ignition module from early failure. Spark plugs are a “window” into the engine and can be a valuable diagnostic tool. The spark plug displays the condition inside the combustion chambers of the engine. The experienced tuner can use spark plugs to find the root cause of problems, determine air-fuel ratios and increase vehicle performance.

A misfire occurs when the spark travels the path of least resistance instead of jumping across the gap. Misfires can be caused by the following: SKU: PLCMR6HX Category: Spark Plugs Tags: 0000-400-7009, 0000-400-7011, 100, 101, 110, 130, 131, 168652-4, 31916-Z0H-003, 3365, 345FR, 439, 526XP, 531008615, 545, 545FX, 545FXT, 545RX, 545RXT, 550XP, 550XPG, 555, 556, 560XP, 560XPG, 562XP, 562XPG, 574519601, 6778, 90119, A425000040, BG56, BG66, BG86, Bosh, BR200, BR500, BR550, BR600, BR700, BT131, Champion, CMR6H, CMR6H-SLDCAP, CS2252, CS2253, CS2258, CS2260, CS2260WH, FC100, FC110, FC56, FC70, FC90, FC95, FR130, FR410, FR460, FR480, FS, FS100, FS110, FS111, FS130, FS131, FS240, FS25, FS260, FS310, FS311, FS360, FS40, fs410, FS460, FS460 C-EM, FS50, FS56, FS65, FS70, FS87, FS89, FS90, FS91, FS94, GX25, HL100, HL90, HL91, HL94, HL95, Honda, HQT-3, HS46, HS46 C-E, HS56, HS56 C-E, HS81, HS82, HS86, HS87, HT100, HT101, HT102, HT103, HT130, HT131, HT132, HT133, HT56, Husqvarna, Jonsered, KM100, KM110, KM111, KM130, KM131, KM56, KM90, KM94, Makita, MS 201 T, MS 201 TC, MS150, MS150 C-E, MS170, MS171, MS180, MS181, MS181 C, MS192 C-E, MS193C, MS193T, MS201, MS211, MS211 C, MS231, MS241, MS241 C-M, MS251, MS362, NGK, Plug, RZ7C, SH200, SH56, SH86, Shindaiwa, Spark, SR200, Stihl, T2600, T435, T540XP, USR4AC Related products If an air-fuel ratio meter or gas analyzer is not available, it will be necessary to visually inspect the spark plugs frequently during the tuning process to determine the proper air-fuel mixture.As a general guideline, among identical spark plug types, the difference in tip temperature from one heat range to the next is approximately 70°C to 100°C. It is most often caused by the wrong (too hot) heat range spark plug, and/or over-advanced ignition timing. An improperly installed (insufficient torque) spark plug can also result in pre-ignition due to inadequate heat transfer.

Illustrations may differ slightly from original product and are not assembled, but in boxes for shipment.

Types of Abnormal Combustion

The heat range must be carefully selected for proper spark plug thermal performance. If the heat range is not optimal, then serious trouble can be the result. The optimal firing end temperature is approximately 500°C (932°F) to 800°C (1472°F). The two most common causes of spark plug problems are carbon fouling (< 450°C) and overheating (> 800°C).

Advancing ignition timing by 10° will cause the spark plug tip temperature to increase by approximately 70° to 100°C. The main differences between the STIHL NGK spark plug (right) and the off the shelf NGK plug (left) are:This spark plug features a triple gasket sealing process that eliminates fuel leakage. It also comprises a solid copper core that gives superior heat dissipation and conductivity. For the best performance from your STIHL tool, we recommend that you always use the STIHL NGK spark plug. Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling. Air (atmospheric) pressure and cylinder pressure decrease as altitude increases. As a result, spark plug tip temperature will also decrease. Spark plugs must provide a path and a location for electrical energy from the ignition coil to create a spark used to ignite the air-fuel mixture. A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug gap. This is called “electrical performance.”