Best spark plugs
Road Master
Joined: Jul 2007
Posts: 792
Likes: 0
From: Niagara Falls, NY
Contrary to advertsing, there is no such a thing as a spark plug that can make HP or offer better fuel economy. OE plugs are designed for optimal performance. Plus using a diffrent plug may change the ion sening on the knock system. OE plugs for HD is Champion copper. I know from GM ecotecs, if you do not use Double platium plugs, it would throw a code for misfire. In HDs it would not do that. But why use something other than copper plugs? I could see uning a platinum, if it was hard to get to the plugs, but in our case it is not so. Diffrent brands are ok, but looking at diffrent brands, Champion has a longer insulater for a hotter burn, compared to others. In my EVO I had to use Champions, for other brands would fould out.
Last edited by molsen; Mar 22, 2009 at 12:35 PM.
Ultimate HDF Member
Joined: Dec 2007
Posts: 9,254
Likes: 283
From: Lake City, Florida (Native)
this is an argument that go on forever and nothing change like an oil thread... But I have found NGK Iridiums the best to liking .. Is what use on my Electra and Sporty both and used it on the Heritage as well with no problems whatsoever...
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Ultimate HDF Member
Joined: Jan 2009
Posts: 5,016
Likes: 277
From: East Tn Foot of The Dragon
dont mess with success, harley plugs are fine, 5 bucks a piece and good for a year. waranty may be a problem if direct cause. dont use any after market plugs wires from what i have read on the forum
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6th Gear
Joined: Dec 2008
Posts: 11
Likes: 0
When I sold my 2000 EGS in January of this year,it had H-D platinum plugs(6r12pp) with 77,000 miles on them and they were still sparking like they were supposed to.The bike had a total of 88,600 miles on it.I did not over use the choke.On a FI bike the plugs should last a long time with many miles on them.