With the countless expensive parts and tweaks we do to get the most out of our little Chinese 2-stroke motors it is easy to overlook the spark plug even though nothing you do will help with a crappy spark.
There are 3 important parts of a spark plug, the sparking tip, the ground electrode, and the insulator.
Until recently, Platinum was considered the best material to use on the top of an electrode because of its durability. However, Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum.
Put that into a harsh environment such as a 2-stroke engine piston chamber, and you have a spark plug that can resist wear much better than platinum. Additionally it is so durable it allowed engineers to produce the world?s smallest center electrode (.4mm) which reduces the voltage requirements, concentrating its sparking power.
For 2 strokes that means even a weak CDI should have a good spark and a good CDI with everything the magneto has via better wiring and you not only get a whopper of a spark, the Iridium can take it.
Also, its smaller size, combined with the tapered ground electrode, allows more room for the flame kernel to develop and produce a more efficient combustion.
The flat ground electrode design of ordinary spark plugs crush the spark, inhibiting its growth; this effect is known as a 'quenching effect.' The simple, but efficient, U-Groove or tapered ground electrode results in better fuel efficiency, improved throttle response, and greater firing energy.
Besides NGK, Champion and Bosh also make Iridium plugs but the one I know that works in most of our 2-stroke China engines is the NGK BPR?HIX Iridium IX.
The ? in the part number is the heat range, which equates to how much insulator material the plug has and refereed to as how Hot or Cold the plug runs.
Part of your spark plug's responsibilities, in addition to firing a spark, is to remove heat from the combustion chamber. This is accomplished by channeling the heat through the insulator material and metal housing. From there, the heat is transferred to the cylinder head where the engine cooling system can go to work.
A spark plug's heat range is its ability to dissipate heat. The 'colder' (higher number) the plug, the more heat it can channel out of the combustion chamber. In a performance application, colder heat ranges may be necessary to handle the extreme temperatures brought on by higher compression ratios, forced induction, and high RPM?s.
While 'Colder' plugs may seem to be the way to go, please remember that the spark plug must achieve its 'self-cleaning' temperature where it can burn off fuel and carbon deposits. Otherwise, the plug could 'foul out' where it is prone to misfiring and poor acceleration.
A plug that is too 'hot' on the other hand can overheat, also causing power loss, detonation, pre-ignition, and possible engine damage.
Here in Arizona I put BPR7HIX's in all my new builds, I can feel the difference and never had to replace a plug yet.
They are hard to find but SBP has them for $9.
One more note, do NOT attempt to gap them, you will snap the tiny Iridium tip off and they come pre-gaped with a cardboard tube around the end to protect it in shipping.
I have been saying I could feel the difference for years, now we all know why ;-}
There are 3 important parts of a spark plug, the sparking tip, the ground electrode, and the insulator.
Until recently, Platinum was considered the best material to use on the top of an electrode because of its durability. However, Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum.
Put that into a harsh environment such as a 2-stroke engine piston chamber, and you have a spark plug that can resist wear much better than platinum. Additionally it is so durable it allowed engineers to produce the world?s smallest center electrode (.4mm) which reduces the voltage requirements, concentrating its sparking power.
For 2 strokes that means even a weak CDI should have a good spark and a good CDI with everything the magneto has via better wiring and you not only get a whopper of a spark, the Iridium can take it.
Also, its smaller size, combined with the tapered ground electrode, allows more room for the flame kernel to develop and produce a more efficient combustion.
The flat ground electrode design of ordinary spark plugs crush the spark, inhibiting its growth; this effect is known as a 'quenching effect.' The simple, but efficient, U-Groove or tapered ground electrode results in better fuel efficiency, improved throttle response, and greater firing energy.
Besides NGK, Champion and Bosh also make Iridium plugs but the one I know that works in most of our 2-stroke China engines is the NGK BPR?HIX Iridium IX.
The ? in the part number is the heat range, which equates to how much insulator material the plug has and refereed to as how Hot or Cold the plug runs.
Part of your spark plug's responsibilities, in addition to firing a spark, is to remove heat from the combustion chamber. This is accomplished by channeling the heat through the insulator material and metal housing. From there, the heat is transferred to the cylinder head where the engine cooling system can go to work.
A spark plug's heat range is its ability to dissipate heat. The 'colder' (higher number) the plug, the more heat it can channel out of the combustion chamber. In a performance application, colder heat ranges may be necessary to handle the extreme temperatures brought on by higher compression ratios, forced induction, and high RPM?s.
While 'Colder' plugs may seem to be the way to go, please remember that the spark plug must achieve its 'self-cleaning' temperature where it can burn off fuel and carbon deposits. Otherwise, the plug could 'foul out' where it is prone to misfiring and poor acceleration.
A plug that is too 'hot' on the other hand can overheat, also causing power loss, detonation, pre-ignition, and possible engine damage.
Here in Arizona I put BPR7HIX's in all my new builds, I can feel the difference and never had to replace a plug yet.
They are hard to find but SBP has them for $9.
One more note, do NOT attempt to gap them, you will snap the tiny Iridium tip off and they come pre-gaped with a cardboard tube around the end to protect it in shipping.
I have been saying I could feel the difference for years, now we all know why ;-}
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