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Title: sparkplugs Post by: John253a on January 26, 2012, 03:25:54 PM just a quick 1
i no there are 2 heads on fe/fc 1 with 5 threads (m14x1.25)=6.25mm thread 1 with 7 threads (m14x1.25)=8.75mm thread 5 thread head use ngk bp4 as standard (use bp5 or bp6 for hot motors) 7 thread head use ngk bp5s (bp6s or bp7s for hot motor) ive been looking through a few ngk book on number/letter representation and both the bp4 and bp5s are the same length plug(3/8" 9.5mm), only difference is the electrode thickness on (s) is 2.5mm ive seen a few running bp5hs (1/2" 12.7mm thread with 2.5mm electrode) on 7 thread heads Whats people thoughts? or are the old numbers of bp5s out of date (meant to be 12.7mm thread) Title: Re: sparkplugs Post by: John253a on January 27, 2012, 03:36:21 PM If people arnt sure on p.no
Do they now why there running, 5 thread head 14x1.25 x9.5mm thread 7 thread head 14x1.25x ___mm thread Another thing are people playing around with the gap on different heat ranges If been recomemend bp6s plugs with a 0.7-0.8mm gap When running near stock with twin carbs and extractors If hot cam bp7s with 0.6-0.7mm If stock with electronic ignition bp5s 0.8-0.9mm gap Stock with points bp5s 0.8mm I was told there us a range for gap as everymotor is different Just wondering what works for others? |