Have been going through different makes of spark plugs bought some new E3 for my custom 04 Sporty has big S&S motor w/ Mikuni 48 HSR carb running straight pipes no baffles approx Dyno 125hp. On premium pump gas. Well any way have been impressed with the E3 so far have been in bike 12 months lot of short rides and I ride hard , still running same ones checked once and gap was within couple thousands of first setting. Just my two cents. Good luck. Wild Bill.
ps E3 come pregapped for my app. At .040 left them there

 

The bigger the gap the more powa. I run my gaps at 50 and 52. 52 on the rear because it's the hitter cyclinder

 

yes this is correct via the Haynes manual.

 

How is .040 out of spec if the range is .038 to .042?

John

 

I suspect you'll have to zoom back in time to 03/17 to find out.

 

Or 4/3/07. I'm sure that the OP has went through many plugs by now and even bikes.