Denso iridium plugs?
Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
In fact, you have to be careful with modern Harleys (07+) because they have an anti-knock system that can be disabled by non-stock plugs.
So you can spend a lot of money on zero improvement and damage you engine in the bargain. Yup, money well spent. Not.
Ultimate HDF Member
Joined: Dec 2008
Posts: 5,120
Likes: 17
From: Indiana
Believe me, I've tried most of them and I can assure you they make zero difference on a Harley. You will also not find any independent testing that shows any difference whatsoever on a dyno.
In fact, you have to be careful with modern Harleys (07+) because they have an anti-knock system that can be disabled by non-stock plugs.
So you can spend a lot of money on zero improvement and damage you engine in the bargain. Yup, money well spent. Not.
In fact, you have to be careful with modern Harleys (07+) because they have an anti-knock system that can be disabled by non-stock plugs.
So you can spend a lot of money on zero improvement and damage you engine in the bargain. Yup, money well spent. Not.
The NGK's are $1 more per plug then the stock HD's and $2 less then the HD platinums. Those that are worried about the money being wasted on iridiums, then why are you guys spending $6 on a $2 champion plug? Gotta have the Harley stamp??
In the end run what you want, but you aren't going to ruin anything with the newer bikes.
Last edited by JaronB; Sep 2, 2012 at 02:38 AM.
Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
If the spark is not the same as that generated with stock plugs then you just don't know what the ECU is going to measure. It might detect extra ions and retard the ignition more often than necessary or it might just not work at all any more and so you won't have this engine-life-extending feature.
Worth it for some dubious benefit of expensive plugs? Not to me.
I went back to stock just to try it and the bike coughed, sputtered and ran rough until the bike was warmed up 10 miles down the road.
Ultimate HDF Member
Joined: Dec 2008
Posts: 5,120
Likes: 17
From: Indiana
Its not about resistance. The anti-knock system works by detecting the ions generated during the spark event. There are more ions generated during knock.
If the spark is not the same as that generated with stock plugs then you just don't know what the ECU is going to measure. It might detect extra ions and retard the ignition more often than necessary or it might just not work at all any more and so you won't have this engine-life-extending feature.
Worth it for some dubious benefit of expensive plugs? Not to me.
If it it ran like that then you either have a fault with the bike or the stock plugs were knackered.
If the spark is not the same as that generated with stock plugs then you just don't know what the ECU is going to measure. It might detect extra ions and retard the ignition more often than necessary or it might just not work at all any more and so you won't have this engine-life-extending feature.
Worth it for some dubious benefit of expensive plugs? Not to me.
If it it ran like that then you either have a fault with the bike or the stock plugs were knackered.
IMO most people are going rebuild it or something else is going to fail before anything goes wrong from a spark plug. Now if you are throwing codes and it runs like crap, I totally understand. But spark plugs are definitely the least of our worries.
When my bike was doing that crap going back to stock plugs was pre exhaust, intake and ECM. It wasn't as bad as it probably read on here, but it was noticeable. It definitely needed to warm up longer. With the iridiums I just fire off and go and it runs the same as if it were warmed up.
Last edited by JaronB; Sep 3, 2012 at 09:36 AM.
Tourer
Joined: May 2011
Posts: 300
Likes: 6
From: South Carolina
My $.02 is we like to set up our Harleys the way we want them. The iridium plug is the latest technology and longest lasting. They should keep your bike in tune a bit longer than standard plugs. On some automobiles with plugs that are hard to get to I would want to be using the longest lasting plugs available. New plugs will start and run better than worn or fouled plugs. So changing your plugs often will help keep your bike in tune. As easy as it is to get to the plugs on a Harley I don't see the point in using anything other than standard plugs. That's just me and there's nothing wrong in someone using something differant that they believe is best on there bike.
Billy
Billy
Stellar HDF Member
Joined: Mar 2006
Posts: 3,124
Likes: 255
From: From Long Island, now in So. Cal
It was a simple question meant to save me a little time finding a decent price without weeding thru a bunch of sites for a good deal on MY spark plug of choice.No need for all the b.s. that's what this site is for right? Sharing information,links etc.? And the whole "a spark is a spark" comments are total bullsh@t...if u haven't tried them shut up! I've used both iridium and platinum plugs as alternatives in all my cars and bikes for years.They last longer,idles smoother,and has a crispier throttle response in most applications.To me that's worth the extra coin.Nuff said.
http://sparkplugs.com/
http://www.phatperformanceparts.com/...so-iridium.htm
Harley Spark Plug Cross-Reference:
http://www.harley-performance.com/ha...park-plug.html
http://www.phatperformanceparts.com/...so-iridium.htm
Harley Spark Plug Cross-Reference:
http://www.harley-performance.com/ha...park-plug.html
Ultimate HDF Member
Joined: Jan 2009
Posts: 5,016
Likes: 277
From: East Tn Foot of The Dragon
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Stellar HDF Member
Joined: Mar 2006
Posts: 3,124
Likes: 255
From: From Long Island, now in So. Cal
These are one-fourth the cost, and they don't have the snake oil logo on them:
Tourer
Joined: May 2011
Posts: 300
Likes: 6
From: South Carolina
With Champion plugs you need to carefully set the gap. They come with the gap way too close for Harley specs. The Harley plugs come with the gap close to being in spec. The dealer close to me sells them for arround $4 a piece but the Champions work fine.
Billy
Billy