depending on plug brand and location of th "r" in the plug number, it can mean "resistor" or "reverse"
most bikes have a resistor in the plug cap on the end of the HT lead...ever wondered what the "5k" meant? BUT!!! as i found on my postie, just wiring the lead to the plug burns out your coil, and your cdi module
...why cars use the resisted plugs usually...
and it stops ya radio making nasty noises... thats also what the condensor does...
with "reverse" plugs, its the way the gap POINTS inside the cylinder...also called "indexing" a plug....
say a champion dj8 and dj8r.... if you compare them, you will find that the gap when installed in your head and tightened to torque, are 180 degrees difference...sounds useless, but in bigger engines makes a huge difference... to do with where the flame front starts in the cylinder....
on that note, a helicopter has twin electrode/ twin plug/ twin magneto systems..... safety, and performance...watch a small piston powered chopper in pre flight checks....(and the audi twin spark?)
start with both magnetos, idles high...switch to one magneto, idle speed drops. back to both...idle high again...switch to other magneto...idle drops again....
these are BIG cylinders, and having the two flame fronts helps for better/more efficient combustion....
yeah, so i was an apprentice chopper mechanic til they moved and i couldnt travel the distance...so what? wish id moved too, years later
China spark plug to NGK
Linear Mode
