NGK Iridium spark plugs

[lightnin]

​Any one use these in your tri glide?

[DK Custom Products]

It's been 5-6 years ago that I tried quite a few different Iridium plugs/performance plugs, including the Screamin' Eagle ones. I found that for myself, on the bikes that I tested, the factory plugs worked best.

I remember, some of the plugs seemed to provide a bit of an improvement at first, but then degraded after a few thousand miles.

Things may have changed since then.

Related to that, I did find that using quality plug wires provided a nice improvement in performance/economy.

Kevin

[Jack Klarich]

I have to agree with Kevin here

After lots of testing different plugs I too come back to stockers

Also Kevin has good info about quality wires

Check any new wires with an ohm meter to compare how they stack up against stock ones, you might be surprised

[rhino 2]

I tried them on my 2011 Tri Glide took them out after only 2 hundred miles 😱 felt like there was a slight hesitation on hard acceleration ?

[ultrafxr]

I think the initial improvement would occur no matter what plug you used as the new plugs should perform better than the old worn plugs you took out. The only benefit of the iridium plugs from what I have seen, heard and read about is longevity but even that is somewhat uncertain. Personally I just stick with the stock plugs and wires. There is really nothing at all wrong with them.

[DK Custom Products]

Years ago I tested well over 100 new spark plug wires, and wrote up a report on the results.

I cannot find it anywhere. If anyone remembers it and can point me to it, I would greatly appreciate it.

Kevin

[Jack Klarich]

Years ago I tested well over 100 new spark plug wires, and wrote up a report on the results.

I cannot find it anywhere. If anyone remembers it and can point me to it, I would greatly appreciate it.

Kevin

I am usually pretty good at finding things, I cannot find it either

What I do remember is that you concluded stock plugs almost always deliver the best performance. You also tested your in stock Screaming Eagle wires and found many out of spec

I agree with your findings having tested many spark plug sets only to find stock is the way to go

[MDO]

I may try the NGK equivalent to the Champion OEM plugs.

I believe they are CR9E.

[Jack Klarich]

I may try the NGK equivalent to the Champion OEM plugs.

I believe they are CR9E.

Iridium # is CR9EIX

I ran NGK in my Streetbob and my 103 Freewheeler

I think they are a very good plug

[Gorilla]

ive got 60k on mine and they are running just as good as to when they were installed SE 110 motor

[MDO]

Iridium # is CR9EIX

I ran NGK in my Streetbob and my 103 Freewheeler

I think they are a very good plug

I was going to try the standard copper plug. This fall/winter I have a lot of maintenance planned.

[MDO]

I may try the NGK equivalent to the Champion OEM plugs.

I believe they are CR9E.

Just an update:

NGK CR9E is not the correct plug for the new M8 motor

I went with the OEM HD plugs & they are fine.

[prariepilot]

I have been running NGK Iridium Plugs in my '13 TG for the last 10K miles with satisfactory results. Performance meets my needs and fuel mileage is running between 36 - 40 mpg. I've attached pictures showing the electrode and ground. They appear to be tan and "fuzzy", indicating they're performing well. What concerns me is the corroded shell. Besides not looking good, is there any other reason to be concerned? I've a new set ready to put in, along with the new wires from DK.

Additionally the H-D service manual says to use a thin coating of anti-seize on the plugs when installing them. NGK says, as do other plug manufacturers, NOT to use anti-seize as it can act as a lubricant altering torque values up to 20% increasing the risk of spark plug breakage and driving the plug too deep in the head. Agree? Disagree



?

[rhino 2]

I have been running NGK Iridium Plugs in my '13 TG for the last 10K miles with satisfactory results. Performance meets my needs and fuel mileage is running between 36 - 40 mpg. I've attached pictures showing the electrode and ground. They appear to be tan and "fuzzy", indicating they're performing well. What concerns me is the corroded shell. Besides not looking good, is there any other reason to be concerned? I've a new set ready to put in, along with the new wires from DK.

Additionally the H-D service manual says to use a thin coating of anti-seize on the plugs when installing them. NGK says, as do other plug manufacturers, NOT to use anti-seize as it can act as a lubricant altering torque values up to 20% increasing the risk of spark plug breakage and driving the plug too deep in the head. Agree? Disagree



?

They.....The rust does look bad, But remember water does collect around the plugs...

Also i do not use Anti -Seize at all....Especially with spark plugs.....I use Heat sink compound on the treads of my plugs....And that's it...

[MDO]

prariepilot, I'm glad the NGK's are working well for you. I know from experience that DK Customs plug wires

improvedmy performance noticablly.

I went with the OEM plugs for my M8. I did not use a thread compound, but I put 1 drop of my spray silicone on my finger and coat the plug threads, then torque to 100 inch pounds.

I also apply dielectric grease to the inside of each new plug wire at both ends, prior to installing them.

After 2 years, my stock plugs looked great & I did not have the external corrosion you had, but my trike doesn't get wet/washed much with water. While I had the tank off to install my new wires, I replaced the 4 plugs.

[prariepilot]

prariepilot, I'm glad the NGK's are working well for you. I know from experience that DK Customs plug

Improves my performance noticablly.

I went with the OEM plugs for my M8. I did not use a thread compound, but I put 1 drop of my spray silicone on my finger and coat the plug threads, then torque to 100 inch pounds.

I also apply dielectric grease to the inside of each new plug wire at both ends, prior to installing them.

After 2 years, my stock plugs looked great & I did not have the external corrosion you had, but my trike doesn't get wet/washed much with water. While I had the tank off to install my new wires, I replaced the 4 plugs.

Thanks for the suggestion on Dielectric Grease on the wire ends. My bike has only seen a wash rack four times since new ('13); I use waterless car wash and S100 Special Surface Cleaner to "wash it". I do ride in the rain quite a bit, most times unintentionally!

I'll find out tomorrow when we go out for the 9/11 Memorial Ride how much the performance/fuel mileage has changed. Getting everything ready today, so no time to ride.

Heads up on the NGK Iridium Plugs! Took them out of the box and checked the gap. Set at .030, not the .038 - .043 the manual calls for.

[Jack Klarich]

Thanks for the suggestion on Dielectric Grease on the wire ends. My bike has only seen a wash rack four times since new ('13); I use waterless car wash and S100 Special Surface Cleaner to "wash it". I do ride in the rain quite a bit, most times unintentionally!

I'll find out tomorrow when we go out for the 9/11 Memorial Ride how much the performance/fuel mileage has changed. Getting everything ready today, so no time to ride.

Heads up on the NGK Iridium Plugs! Took them out of the box and checked the gap. Set at .030, not the .038 - .043 the manual calls for.

Check Walmart by the automotive lighting section for dilectric grease

[jackthemachinist]

I have a DFT trike built out of a 1997 Electraglide Classic, with an S&S 111 touring motor. It has been a starter since I installed the motor. Runs great, plenty of power, but hard to start. I could never get the right amount of choke and carburetor "squirt" figured out, hot or cold, just grind, grind, grind. Installing new factory-recommended plugs would help for a short time, but within in 1000-2000 miles back to the same. The plugs never showed any excess deposits, rich, lean, anything, although a slight amount of electrode wear, nothing abnormal.

I've never had any luck with "magic" sparkplugs, but many new cars now come from the factory with iridium plugs, presumably to make those 50-100,000 mile recommended service intervals. So I decided to try a pair.

I put a set of Autolite iridium plugs in the trike, and it started right up. VAROOM! I could hardly believe it. It never started like that before. They've only been in for a few thousand miles, but it is far easier to start than it ever was before. Push the button and it fires right up, every time, just like it ought to.

I don't know about magic, but these plugs sure work in this application.

They workded so well, I put a set in my mildly hopped up 2001 Softail. I wasn't having any problems with it, but it was time for a new set of plugs so I put in iridiums. Starts the same, runs the same. Maybe they'll last longer, who knows.

I doubt there's all that much difference between brands of plugs. I use Autolites because I have had very good luck with them in racing may years ago, and have never had a problem.

The the iridiums sure solved the problems with my S&S-powered trike.

That's my experience. I never thought a different type of plug would make any difference at all, but it sure did in this case.

[MDO]

I have a DFT trike built out of a 1997 Electraglide Classic, with an S&S 111 touring motor. It has been a starter since I installed the motor. Runs great, plenty of power, but hard to start. I could never get the right amount of choke and carburetor "squirt" figured out, hot or cold, just grind, grind, grind. Installing new factory-recommended plugs would help for a short time, but within in 1000-2000 miles back to the same. The plugs never showed any excess deposits, rich, lean, anything, although a slight amount of electrode wear, nothing abnormal.

I've never had any luck with "magic" sparkplugs, but many new cars now come from the factory with iridium plugs, presumably to make those 50-100,000 mile recommended service intervals. So I decided to try a pair.

I put a set of Autolite iridium plugs in the trike, and it started right up. VAROOM! I could hardly believe it. It never started like that before. They've only been in for a few thousand miles, but it is far easier to start than it ever was before. Push the button and it fires right up, every time, just like it ought to.

I don't know about magic, but these plugs sure work in this application.

They workded so well, I put a set in my mildly hopped up 2001 Softail. I wasn't having any problems with it, but it was time for a new set of plugs so I put in iridiums. Starts the same, runs the same. Maybe they'll last longer, who knows.

I doubt there's all that much difference between brands of plugs. I use Autolites because I have had very good luck with them in racing may years ago, and have never had a problem.

The the iridiums sure solved the problems with my S&S-powered trike.

That's my experience. I never thought a different type of plug would make any difference at all, but it sure did in this case.

Try the plug wires that DK Customs sells. You will be amazed.

[MDO]

prariepilot, Thanks for the tip on checking the plug gap. It's a little different gap space for the M8, but the HD dealer told me they were gapped already, but I always set mine to the lower end of the gap range, in case they open up a little.

Trust, but verify.

Have a great Memorial ride tomorrow!