Best plug for s9

[Superstu]

Just wanted to see what plug ppl run in there super 9? Does the hix burn hotter then like brs7hs? I or if the heat range is 7 on both plug its the same. I just don't want to put iridum plug in and melt my piston.

Thanks
stu

[wordslinger]

...iridium wont do that...

i run, and pretty much everybody else i know, the NGK br8hs, or br8hsa...


                               


..the (7) is a hotter plug than the 8 anyway...

[Superstu]

I just don't want to burn a hole in my piston again. I thought the iridum was one of the reasons I melted it.

[wordslinger]

..more likely, a lean fuel mix....


               

[MotoRandy123]

 The temperature of the plug determines how fast it flows heat into the head. A hot plug
flows more slowly. If too hot it could light the incoming mixture before the proper time.
Racers use a colder plug as they are at WOT more and so the plug heat could cause
preignition. Note: some manufactures use a higher number for hotter and some a lower
 number!

 A 2 stroke burning a hole in the piston is too lean. Unfortunately they make the most power
just as they're about to melt! That's why we do plug chops and jet on the rich side. As conditions
change so does your mixture. Cold air = more oxygen so needs more fuel to remain at the same
 mix level.