[TomM]

The major structural difference affecting the heat rating is the length of the insulator nose. A hot-type spark plug has a longer insulator nose. The insulator nose of a hotter spark plug has a longer distance between the firing tip of the insulator and the point where insulator meets the metal shell. Therefore, the path for the dissipation of heat from the insulator nose to the cylinder head is longer and the firing end stays hotter. The insulator nose of a hotter spark plug also has a greater surface area that is exposed to more of the ignited gases and is easily heated to higher temperatures. A colder spark plug functions in an opposite manner. here

[nviera174]

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be replaced and the fouling cause identified. [links]

[sentry360]

The most serious result of selecting a heat range that is too hot is overheating. Overheating will cause the electrodes to wear quickly and can lead to pre-ignition. Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs. When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur. Pre-ignition will dramatically raise the cylinder temperature and pressure, which can cause serious and expensive engine damage. When inspecting a spark plug that has experienced overheating or pre-ignition, blistering on the ceramic insulator and/or melted electrodes can sometimes be found.

[r4king]

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.

[ellimistd]

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). [links]

[ruenma7411]

A hotter heat range spark plug has an insulator design with a longer heat flow path to the metal shell of the plug. As a result, more heat stays in the ceramic firing end and less is dissipated to the engine. A colder heat range spark plug has an insulator design with a shorter heat flow path to the metal shell of the plug. As a result, less heat stays in the ceramic firing end and more is dissipated to the engine. For a spark plug to function properly, it must have a tip temperature high enough to burn off carbon deposits (self-cleaning) and avoid fouling, while remaining low enough to avoid overheating the ceramic firing end and pre-ignition.

[earleenproehl]

One of the most misunderstood aspects of spark plugs – is the heat range. One misconception is that the heat range is related to the spark temperature or intensity. Another common misconception is that the spark plug is designed as a heat sink to “remove” heat from the combustion chamber. These ideas are both false. The spark plug is heated during combustion and must dissipate that heat to the cylinder head at a certain rate to avoid overheating the ceramic firing end. The spark plug heat range only indicates the rate that the spark plug dissipates its firing end heat to the engine. more

[BitcoinCyberStore.com]

For most vehicles, the factory recommended heat range is sufficient; however, on some modified or special-use engines, alternative heat ranges may be necessary. Often hotter heat ranges have been used to address a fuel delivery or oil consumption problem. Installing a hotter heat range plug will reduce the pre-ignition safety margin, so it is better to correct the mechanical or tuning issue instead of changing the plug heat range.

[otalesak]

[shadowdust]

[Ostrich09]

[franzl]

It is always nice to fire up the old girls with new plugs. For the 12.00 that it costs it is a minor cost for piece of mind as well as you can throw the old ones in the tool box under the seat if you need a spare. [links]

[AnonyMouse]

I do not know what the gap range is. I have been told by other users that the factory gap is fine with the B8ES.

[bitk]

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[30dirtybirds]

I've used both and I did not notice any performance change in my 82 GPZ1100 B2, but I have the stock ignition system
and can't comment or different coils or other ignition parts. more

[krs]

I usually change them out at the start of every season. [links]

[awwright]

A tighter ignition gap may tend to squish the spark kernel and a wider one may be almost at the limit to produce a useable spark. I like the in between gap. more

[ontarioloans]

Find the right Champion RJ19LM Spark Plug OEM Part for your small engines at LawnMowerPros. Purchase the Champion RJ19LM Spark Plug you need to repair your equipment today. LawnMowerPros has the Champion spark plugs for your small engines.

[djclintoris]

This product is an OEM Part. here

[xterm11]

FITS:
- Club Car With Kawasaki 8.2 HP
- Green Machine 4000, 4500(with 1/2" reach)
- Honda F28, F400, G40, G41, G42, G65, GS65, G80, GV150 >2029058 (mag)
- Kawasaki KF24, KT43, KF53D,DA
- Subaru-Robin 2-Cycle EC05-2, EC07, EC07-2, EC25, EC37-3, EC06, EX13, EH18-VX, EH18VX-2, EX17, EX21, EX27, EY10, EY13, EY13-2, EY14, EY18, EY18-2, EY18W, EY12W, EY25 with gasoline, EY15, EY15V, EY20, EY20V, EY28, EY44, EY21
- Tecumseh OHM120 spec #220000 to 223999, OHSK110 (spec #222999 and lower), OHSK120 (spec# 222999 and lower), OHSK130 (spec# 222999 and lower), OVM120, OVXL/C120 (spec #202700 to 202999), OVXL120 (spec #202700 to 202999), OVXL125 (spec #202700 to 202999)
- Wisconsin-Robin W1-145, W1-185, EY18-3W (gasoline), EY44W, WO1-115, WO1-150, WO1-210, WO1-300, W01-300V, WO1-340, WO1-340V, WO1-430V, WO1-510, WO1-560, WT1-125V, W1-145V, W1-185V, W1-450V
- Wisconsin Robin WI-390 without solid state ignition
- Yamaha G1 thru 1982
- and others [links]

[Inedible]

REPLACES:
- Autolite 2656
- Bosch W8AC
- Denso W16FS-U
- NGK B6HS
- and others

[dianamonte03]

CHAMPION RJ19LM RESISTOR TYPE SPARK PLUG

[Comatus]

REPLACES:
- BOSCH WR11E0
- BRIGGS & STRATTON 29693, 492167, 492167S
- DENSO W9LM-US
- NGK B2LM, BR6ES
- and others more