Spark plug time
Road Warrior
Joined: Sep 2011
Posts: 1,311
Likes: 1
From: -
I've done extensive research and it came down to this exactly. On newer models you cannot change the sparkplugs from the original HD, unless you have a way of measuring the impendace on an after market plug to be the same as the original HD plug for the antiknock system to work correctly.
Thread Starter
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Extreme HDF Member
Joined: Sep 2006
Posts: 10,114
Likes: 29
From: Vancouver B.C. Canada
Rode my bike last nite, the spark plugs work great, no more backfiring, yeah they are 5 years old, too lazy to change them 
. These champion RA6HC are the exact part number, I don't hear any pinging, lack of power etc, I will just leave it. Thanks!
. These champion RA6HC are the exact part number, I don't hear any pinging, lack of power etc, I will just leave it. Thanks!
Road Warrior
Joined: Sep 2011
Posts: 1,311
Likes: 1
From: -
i've just checked, it's the same specs for 96 and 103 regarding plugs
Road Master
Joined: Nov 2006
Posts: 1,164
Likes: 401
From: Port Coquitlam B.C.
I just put in some Harley plugs for the first time in about 4 years. I've been using NGK plugs. Absolutely no difference in how the bike runs. That myth about needing Harley plugs for the anti knock to work is just that, a myth.
Ultimate HDF Member
Joined: Apr 2008
Posts: 5,384
Likes: 12
From: Out on Deranged
Good to know for next time!
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Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
Its a system for maintaining the long-term life of the engine by eliminating transient knock events. Its not a system designed to tune around gross knock that you can hear that is the result of incorrect timing or fuel tuning.
Its not a myth. The anti-knock works by measuring the resistance through the coil, the plug leads and the plugs. This is obviously extremely sensitive to be able to detect the resistance change due to a knock event. Mess with any of these components and its likely you will prevent correct operation.
Performance or other enhancements from non-stock sparkplugs are the myth. You will not find a dyno chart posted by anyone independent that shows a performance boost from non-stock plugs.
Road Master
Joined: Nov 2006
Posts: 1,164
Likes: 401
From: Port Coquitlam B.C.
Seeing as the usual ping event being detected lasts for less than a second, you really have no idea if the bike's anti-knock is still working or not.
Its a system for maintaining the long-term life of the engine by eliminating transient knock events. Its not a system designed to tune around gross knock that you can hear that is the result of incorrect timing or fuel tuning.
Its not a myth. The anti-knock works by measuring the resistance through the coil, the plug leads and the plugs. This is obviously extremely sensitive to be able to detect the resistance change due to a knock event. Mess with any of these components and its likely you will prevent correct operation.
Performance or other enhancements from non-stock sparkplugs are the myth. You will not find a dyno chart posted by anyone independent that shows a performance boost from non-stock plugs.
Its a system for maintaining the long-term life of the engine by eliminating transient knock events. Its not a system designed to tune around gross knock that you can hear that is the result of incorrect timing or fuel tuning.
Its not a myth. The anti-knock works by measuring the resistance through the coil, the plug leads and the plugs. This is obviously extremely sensitive to be able to detect the resistance change due to a knock event. Mess with any of these components and its likely you will prevent correct operation.
Performance or other enhancements from non-stock sparkplugs are the myth. You will not find a dyno chart posted by anyone independent that shows a performance boost from non-stock plugs.