Your right they call for a 0.04 gap from ngk. The v-rod calls for a 0.035 gap using Harley's plug. I think either way your safe but in years past I have learned that gaps too wide can cause a low rpm stumble in many engines so that is the reason I suggested the same gap that Harley calls for. I also run ngk plugs in mine and have mine gapped at 0.035 and the last set I installed in rspencers bike came gapped at 0.035 and we only checked them before we installed them. Either way I think he is safe with either gap and no one was saying you were wrong by any means.rogerdata said:I don't mean to be argumentative but I did not post this without checking first. Please see the jpg below. The info can be found at http://www.ngksparkplugs.com/apps/motorcycles/make4.asp?id=848&type=ir
just a caution. sometimes platinum or iridium spark plugs can fool the knock sensor into thinking the motor is detonating . if you loose power when you put them in this is why. i have seen some spark plugs cause the ion sense to pull so much timing that the motor is down 20 hp. of course you can disable the knock sensor with the sert.rogerdata said:I am running the iridium plugs. I went with the NGK recommended gap of .040.
Beware that these plugs are very fragile and even the smallest gap measuring touch can break the center electrode!:banghead: