Ok i've tried this before with failed results, currently im running NGK BKR6E which is stock heat range and its a copper plug I'm also running .040 gap.

I've tried BKR7E plugs at gaps anywhere from .035 to .045 and I got knock in every gear under load, whats the right plug and gap for this setup??????

 

I ran 25 psi on that plug to the tune of 22* once i went to 28 psi it started to blow out in 3rd i tried 2steps colder iridium and the same thing happen so i ended up pulling some timing for pump gas. Those plugs should handle your power just fine.

 

Try the BKR7EIX iridium plugs 1 step colder. I gap'd them at .028-.030 with a 2.7 pulley runs awesome no spark blowout! I have friend with hybusa motor bikes with turbos and they run in the low 8sec range...they swear by the NGK iridium plugs thats all they use.

 

im running the 2.75 pulley right now on the 7e's gapped to .028. max timing is 21.5-22 degree's i think

zero knock from 40-150mph

 

so stick with the BKR6E?

 

Bkr7's. Close the gap. You have them open too much.

 

He definately has them too open, but at 6e with a 30 gap should work pretty well for anyone with decent support for their HTV1320s. That is assuming he is still running gasoline as a fuel, of course.

 

7e's gapped down at either .32 or .30. Don't remember right off hand. No knock

 

ah ok ill give that a try