Better SPARK PLUGS for HD 103cc motor?

[tbear]

Been thinking of changing Spark Plugs on my 2010 Triglide with the 103cc motor.
Have the Stage 2 work done on it already. Have the regular plugs in it now but was thinking of putting in E3 plugs plus 8mm plug wires. No gapping envolved and making better spark (I was told). I don't think it will mess up my Dyno. Any Opinions???

[PIGGI]

I've heard that some plugs can mess with knock sensor system since the plug functions as the sensor. Plugs are cheap and I change mine every 5k so I stick with stock HD.

[jackthemachinist]

There ain't anything magic about spark plugs....

[Mr.Wizard]

I've heard that some plugs can mess with knock sensor system since the plug functions as the sensor. Plugs are cheap and I change mine every 5k so I stick with stock HD.

Aftermarket or even SE plugs and wires will mess with your ion sensing system on the EFI. Stay with stock. Even a high performance motor will run fine on stock plugs and wires.

[DK Custom Products]

Aftermarket or even SE plugs and wires will mess with your ion sensing system on the EFI. Stay with stock. Even a high performance motor will run fine on stock plugs and wires.

What do you mean "will mess"?

I have run SE Wires and Taylor Wires (made for HD EFI bikes) on many different HD EFI bikes and never seen any degradation in the operation of the ion sensing system.

Please explain.

btw, I have tried many different plugs over the years...always go back to the stock plugs...have not tried a non-stock plug in a couple of years now. I did see a few different plugs cause issues with the ion sensing.

Kevin

[Lizard]

Some bikes, not all, will throw codes with anything other than the stock plugs. Wires shouldn't cause the problem on any bike. No way to tell if you're gonna throw a code without trying the plugs out. Fact is, the difference between the spark plugs, including the idea of indexing them, makes such a slight difference that you wouldn't notice it even on a dyno, let alone seat of the pants.

I agree with Wiz, stick with the stock plugs, change them every 10-15k miles.

[Mr.Wizard]

Explain?

Well, OK

Aftermarket wires may or may NOT have the same resistance, just like aftermarket spark plugs. This will create a feedback to the ECM as it looks for a certain modulation frequency for spark. This is how it knows if there is pre-detonation or knock retard or abnormal combustion.

With the built in Knock Retard Tables set to learn (all are by default) any misreading of the ion system will show up as a possible/ghost knock. The ECM remembers this along with the real knock. As you ride these KR Tables will remember where the knock was and when you ride in that kPa and RPM again the ECM will automatically reduce your spark table for that cylinder. If it continues to read this ghost knock your spark tables will continue to go down.

Now, as you key off and key on these tables are eventually reduced. If you have extenuating circumstances such as bad gas these tables will return to normal when you fill up or add booster but if you have plugs or wires that are not the correct resistance... your ECM will not be able to tell the difference thus it will remove spark for you to protect your motor like it or not, that is, unless these tables are turned off. This is a motor safety protection entry so I hope no one turns it off.


-Wiz

[Mr.Wizard]

Some bikes, not all, will throw codes with anything other than the stock plugs. Wires shouldn't cause the problem on any bike. No way to tell if you're gonna throw a code without trying the plugs out. Fact is, the difference between the spark plugs, including the idea of indexing them, makes such a slight difference that you wouldn't notice it even on a dyno, let alone seat of the pants.

I agree with Wiz, stick with the stock plugs, change them every 10-15k miles.

I had an 09 Shark nose here for motor work and tuning. When he brought it in he said he would lose his radio and speedo. Would go along just fine then poof... nothing. After the motor work and tuning everything looked just fine. He called me after he got home and said the radio and speedo went back out. Cranked the bike back up and all was fine but it was running rough.

I reflashed the bike again remotely. Bike ran good again...

About a month later he rode to Florida with some buddies and the radio and speedo went out again. He called me as he was getting about 25 MPG. I had him reflash the bike, all was good. Since the radio was from Iron Cross he called them while in Florida. When they found out he had aftermarket plug wires and plugs they asked him to replace them with stock. I believe that was about 3 years ago. No problems since. After researching what the problem could have been... well, let's just say I'm nowhere near perfect but more educated everyday.

[Peter A.]

I've wondered numerous times about changing plugs/wires - Wiz ,
you sure explained it all, many thanks for your excellent info,

[DK Custom Products]

Explain?

Well, OK

Aftermarket wires may or may NOT have the same resistance, just like aftermarket spark plugs. This will create a feedback to the ECM as it looks for a certain modulation frequency for spark. This is how it knows if there is pre-detonation or knock retard or abnormal combustion.

With the built in Knock Retard Tables set to learn (all are by default) any misreading of the ion system will show up as a possible/ghost knock. The ECM remembers this along with the real knock. As you ride these KR Tables will remember where the knock was and when you ride in that kPa and RPM again the ECM will automatically reduce your spark table for that cylinder. If it continues to read this ghost knock your spark tables will continue to go down.

Now, as you key off and key on these tables are eventually reduced. If you have extenuating circumstances such as bad gas these tables will return to normal when you fill up or add booster but if you have plugs or wires that are not the correct resistance... your ECM will not be able to tell the difference thus it will remove spark for you to protect your motor like it or not, that is, unless these tables are turned off. This is a motor safety protection entry so I hope no one turns it off.

-Wiz

Thank you for clarifying.

I thought I was missing something.

Up until recently, DK Custom Products was the single largest purchaser of SE Wires world-wide. Years ago we tested the SE wires and they had the same resistance as the stock wires. Same with the Taylor wires we sell.

At the same time Moco made the new rule of no wholesaling to Non- HD Dealers, they also raised the retail price on their SE wires by $5 a pair (a 25% increase!), AND we have noticed a higher percentage of DOA's.

I think it is time to retest the resistance on the SE's, and double check the Taylors again too.

Kevin

[msocko3]

Few years back my 06 Ultra started running ratty, would ping miss and sometimes pop. Chased it a bit until I did some data logging and found 13 degrees timing being pulled when it would go into one of its fits. A new set of plug wires was just what the Dr ordered. The funny thing was the resistance wasn't to far from spec, goes to show sometimes a little means a lot in some cases.

[Mr.Wizard]

Here's something else to digest.

The newer model the leaner.
The leaner model the greater chance of real knock.
The greater the chance of real knock the higher the risk of ghost knock with non-compliance plugs and wires.


See where I'm going with this?

When a person gets heavily involved with tuning bikes as I do you hear/read complaints about the tuning device. The TTS did this or the PV did that when reality it was something they added to the bike and not the tuning device at all.

To be honest I had no idea you even sold wires as I've never been to your website nor do I ever intend on hurting the sales of any sponsor/vendor. I hate to knock your plug wire sales down Kevin (pun not intended) but the most people get out of fancy wires is the look. What you have going for you is most purchase for the look while thinking they are getting something better in the performance category. In reality they could be bolting on slow timing death IF the resistance range isn't correct.



-Wiz out

[tbear]

Well ! -It's good to get a Good Conversation going !! Thank you all for the information and feed back...I guess I better STAY with the ORIGINAL plugs and wires....

[Buddy WMC]

I'm running the SE plug wires with the stock HD plugs and have had no problems. I only changed the plug wires for looks. Just changed the plugs for the hell of it and with this 10% ethanol fuel, it's difficult to get a reading. We do no however, with our V-Tunes and Histograms know that the tune is right on the money and the bike runs great. Therefore, I'm leaving her alone.

Wiz,
Did you know that HD replaced my entire primary drive? The only thing that was not ruined was the chain. All new late model parts installed including the 2014 comp, but they pulled my extra plate clutch, Hayden Tensioner and ClutchWiz. They did reinstall the SE spring I had as it was an HD part. Now I have a rattling sound like lifters or rockers until I pull the clutch in and the noise goes away. Any input as they want me to bring the bike back in for a test ride? Good dealer as they covered everything under the ESP without any questions about the mods. They believe that the Hayden tensioner caused the problems,but I'm noy buying that. My stock tensioner had the same wear pattern as the Hayden, but they put a new upgraded HD tensioner back in. Kathy from Hayden is sending me the newest modified Hayden.

[Mr.Wizard]

That's their job, to put all stock parts back in due to your extended warranty.

Your issue wasn't the Hayden, CW or extra plate clutch pack. It was the compensator from the beginning. I also highly suggest you put in the 480 spring like the rest of us are doing who have the complete combination. Lever pull is the same as the SE spring but you have more lever friction zone with the 480. TGlideStuff.com has the spring for much less than anyone else.

What to do because of the test drive? Let them test it then put it all back in.

[TomWoodgeard]

I am respectfully going to disagree with most of the replies.

I feel that the H-D plug specified for the Twin Cams is too hot (Federal Emissions)

So, for the last 12 years, I have been using a colder NGK plug DPR9EVX-9
(NGK stock # 3854) with excellent results. This is an irridium plug with a fine wire electrode.

They are NOT cheap (List price $9.07 - NAPA price $8.59 and they have to be ordered), but I feel that the head temps are reduced slightly with colder plugs.

I installed them on my 2013 Anniversary Tri Glide along with a Cobra Powerpro Tuner, Arlen Ness Big Shot air cleaner (Stock Anniversary cover), and Rush 1.75 mufflers. I have yet to have any pinging and oil temps haven't exceeded 230 degrees.

When I took the stock plugs out, they were bone white. The NGK are tan, and were tan before I installed the other stuff.

Installing the NGK plugs always has been the FIRST thing I did to any of the Twin Cam bikes I have owned. (5)

[msocko3]

I am respectfully going to disagree with most of the replies.

I feel that the H-D plug specified for the Twin Cams is too hot (Federal Emissions)

So, for the last 12 years, I have been using a colder NGK plug DPR9EVX-9
(NGK stock # 3854) with excellent results. This is an irridium plug with a fine wire electrode.

They are NOT cheap (List price $9.07 - NAPA price $8.59 and they have to be ordered), but I feel that the head temps are reduced slightly with colder plugs.

I installed them on my 2013 Anniversary Tri Glide along with a Cobra Powerpro Tuner, Arlen Ness Big Shot air cleaner (Stock Anniversary cover), and Rush 1.75 mufflers. I have yet to have any pinging and oil temps haven't exceeded 230 degrees.

When I took the stock plugs out, they were bone white. The NGK are tan, and were tan before I installed the other stuff.

Installing the NGK plugs always has been the FIRST thing I did to any of the Twin Cam bikes I have owned. (5)

I have to say for the last 12 years you've gotten lucky running 2 steps colder plug, the lean AFR has saved you from possible fouling. Since 1986 which is before the Twin Cam Harley Davidson has been installing the same spark plug in their big twin engines. The EVO which ran the very same spark plug wasn't designed as an emissions engine so Federal Emissions isn't the reason they choose the plug they use.

Spark plug heat rang doesn't have any bearing on oil temperatures. Heat range too hot can in some cases cause pre-ignition or in extreme cases premature spark plug wear. A plug that is to cold can suffer from carbon fouling. As for head temps, I don't think a cooler plug has any impact on them, if anything a colder plug could raise head temps because it will shed more of its heat into the cylinder head. For the most part you will have to use more sophisticated equipment than the normal shade tree mechanic has available to tell a difference in head temp between the correct heat range plug and a plug 2 steps colder.

FWIW I don't get all caught up in the special electrode mumbo jumbo such as iridium, platinum etc. A straight up no frills spark plug will get the job done as well, and last just as long as the expensive spark plugs, the biggest difference between them is will be your wallet will be lighter with the fancy spark plugs.

With that being said. I run NGK spark plugs, there are only 3 reasons I do so. 1: is I have tested to make sure the plug I choose isn't messing with my ION sensing. 2: I like the fact they don't discolor, oxidize and show rust stains like the stock HD plug does. 3: I'm used to reading NGK spark plugs and grew quite fond of them from when I was tuning my brothers blown alcohol dragster. As for reading them, modern gasoline doesn't lend it self well for plug reading.

The plug I run, DCPR8E which is 1 step colder. I started running this particular heat range in a high compression 95" build I had in my 06 Ultra at the time, I now run them in the 120" engine I have in the same bike. I also have been installing them in my dads 09 Triglide with no issues.

[tbear]

I have to say for the last 12 years you've gotten lucky running 2 steps colder plug, the lean AFR has saved you from possible fouling. Since 1986 which is before the Twin Cam Harley Davidson has been installing the same spark plug in their big twin engines. The EVO which ran the very same spark plug wasn't designed as an emissions engine so Federal Emissions isn't the reason they choose the plug they use.

Spark plug heat rang doesn't have any bearing on oil temperatures. Heat range too hot can in some cases cause pre-ignition or in extreme cases premature spark plug wear. A plug that is to cold can suffer from carbon fouling. As for head temps, I don't think a cooler plug has any impact on them, if anything a colder plug could raise head temps because it will shed more of its heat into the cylinder head. For the most part you will have to use more sophisticated equipment than the normal shade tree mechanic has available to tell a difference in head temp between the correct heat range plug and a plug 2 steps colder.

FWIW I don't get all caught up in the special electrode mumbo jumbo such as iridium, platinum etc. A straight up no frills spark plug will get the job done as well, and last just as long as the expensive spark plugs, the biggest difference between them is will be your wallet will be lighter with the fancy spark plugs.

With that being said. I run NGK spark plugs, there are only 3 reasons I do so. 1: is I have tested to make sure the plug I choose isn't messing with my ION sensing. 2: I like the fact they don't discolor, oxidize and show rust stains like the stock HD plug does. 3: I'm used to reading NGK spark plugs and grew quite fond of them from when I was tuning my brothers blown alcohol dragster. As for reading them, modern gasoline doesn't lend it self well for plug reading.

The plug I run, DCPR8E which is 1 step colder. I started running this particular heat range in a high compression 95" build I had in my 06 Ultra at the time, I now run them in the 120" engine I have in the same bike. I also have been installing them in my dads 09 Triglide with no issues.

I am alittle confused here. You tell the man that running colder plugs is not good but YOU run a step colder plug. I understand the other stuff but then you say a step colder heat range is better. Maybe not 2 or 3 steps higher then???

[TomWoodgeard]

All I can say is.....That there were tests run many years ago about Harley's plugs being too hot. Might have been Kip Woodrig (Woodring)? from Thunder Press who knew of someone that did EXTENSIVE testing on the effects of spark plug heat range on twin cam engines. Yes.... the same H-D plug was run on Evos....but even then, California emmissions compliances were WAY ahead of the Federal Government's.

I am NOT trying to stir up a pot of sh*t, I'm replying to the original poster's question. There IS more than meets the eye.

MY experience is VERY positive on running colder NGK plugs in Harleys.
I have NEVER fouled a NGK plug, but I have seen friends, back in the day, foul Harley plugs

(Now I shall jump off my soapbox....(LOL)

- - - Updated - - -

Sorry, One more thing..... To the Original Poster.... Take out your plugs, they will be white. Install the NGK plugs I mentioned, ride for 500 miles, take them out. They will probably be tan. THAT'S a step in the right direction!!

[DK Custom Products]

Few years back my 06 Ultra started running ratty, would ping miss and sometimes pop. Chased it a bit until I did some data logging and found 13 degrees timing being pulled when it would go into one of its fits. A new set of plug wires was just what the Dr ordered. The funny thing was the resistance wasn't to far from spec, goes to show sometimes a little means a lot in some cases.

Do you happen to remember how far from spec they were? Reason I ask is that the stock cables have a fairly large acceptable range, according to manual, of 8688-23,178 on the front cylinder and 4188-11,172 on the rear.

It makes sense that if it was out even by 100 on either side, it would not fit the parameters in the ECM and result in retarding. Just curious how far out of those wide parameters your wires had gone.

Here's something else to digest.

The newer model the leaner.
The leaner model the greater chance of real knock.
The greater the chance of real knock the higher the risk of ghost knock with non-compliance plugs and wires.


See where I'm going with this?

When a person gets heavily involved with tuning bikes as I do you hear/read complaints about the tuning device. The TTS did this or the PV did that when reality it was something they added to the bike and not the tuning device at all.

To be honest I had no idea you even sold wires as I've never been to your website nor do I ever intend on hurting the sales of any sponsor/vendor. I hate to knock your plug wire sales down Kevin (pun not intended) but the most people get out of fancy wires is the look. What you have going for you is most purchase for the look while thinking they are getting something better in the performance category. In reality they could be bolting on slow timing death IF the resistance range isn't correct.



-Wiz out

Wiz, great info, and I appreciate it. We have NO desire to sell wires outside of spec. This thread has sent me on a search to learn more about the ion sensing. I had an elementary grasp of it before. Now, after hours of reading, I have a much better grasp on it.

I tested some used wires I have here at home, and I also tested all the wires currently on my bikes here. Some stock, some SE and some Taylor. All tested at the lower end of the specs, except for one of the new SE (6 months old) wires on my Softail. It tested out 2000 over max acceptable per the manual. (which probably explains why I've been less than happy with my auto-tuning on this bike)

Next week I will be in the parts room at a Dealership testing a good number of their SE wires and their OEM wires. Will also pull some of the new models on the floor and give them a test. I want to get some data on what they are measuring at new from HD...both the OEM and the SE.

This weekend I will be hitting 50-100 random sets in our shop, recording all the readings.

Again, thank you for prodding me to research this more fully.

If I can, I have a couple more questions for you?

In my research it appears that other factors, besides plugs and plug wires, can/do have an effect on the Ion Sensing feedback, and thus, how the ECM may sense pre-det. Higher compression, aftermarket cams, even non-stock AFR's are mentioned as variances from stock that will affect the ECM interpretation of the Ion sensing feedback, possibly resulting in timing retard that is unnecessary.

Is it possible to change the values in the ECM that represent knock in a stock engine so that a non-stock (say a Stage II) can still have the timing retard enabled and not sense "ghost knocks"?

TIA for any info/thoughts on this subject.

Kevin