Doc, just bought a 2019 FLDE, 489 miles. Last HD I purchased was a 04 super glide. I find your maintenance videos very helpful with sincerity & honesty. It appears you have a lot of experience & wisdom on HD motors new & older models Thanks for all the assistance & advice.
I just changed plugs and wires yesterday. I went with stock plugs and Symax 8mm red wires. My 96 ci 07 FXSTC has a Stage 1 mod. I gapped the plugs to 38 as Doc recommended. Test ride was AWESOME. She definitely runs better and responded quicker. The plugs I pulled were about 43 so at the max gap. Thanks Doc for YOUR infinite wisdom!
Doc, I know that I am a bit late to everything. I have a 03 fat boy. So I am new . I love it as everyone else does. I want to thank you for your videos. You are giving me a ton of information. No way can I ever thank you enough Sir!!!
NGK spark plugs feature what is known as ‘trivalent plating’. This is a silver-or-chrome coloured finish on the threads that is designed to provide corrosion resistance against moisture, chemicals and weathering. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage
It's not a bad idea to have some antiseize compound on the thread of the sparkplug, but you have to compensate for the torque-value. This is a good advice you gave. Thank you for sharing your experience and background story. 👍👍👍👍👍. Greetings from The Netherlands
It amazes me how many people don't know how to do simple maintenance. Thanks for helping the world be a little bit more aware of proper care of their scooters
Going to get spark plugs from the dealership right now thank you for sound advice and taking the time out to do these videos they greatly help us who aren't professional mechanics but can at least do minor repairs and upgrades
Russell Linthicum this is true. I just bought a 2005 Sportster, with 11,000 miles on the clock, on the original front tyre. I’ve just replaced the tyre and the plugs too. Not too sure whether 15 years is a very good service interval though. 🙂
Good info .Spark plugs can be cleaned and gap can adjusted. Riding for over 25 years. Plugs have never been a problem. I only had one ever fail completely. A little maintenance goes a long way . .
My Ultra Limited was getting hard to start at 14,000+ miles. Initially thought it was the battery as it is the original battery on a 2016. Decided to put in new plugs and what a difference. Bike fires right up and the power on the road is back. I didn’t realize the amount of power loss the old plugs were causing. I’m going to go with Doc’s advice and replace the every 10,000 miles from here on out.
Check plug tops, make sure they are tight. Anti seize threads, and a little dielectric grease on plug top and a little in the boot for ease of slip on. Champion Spark Plug Chart shows you how "Spark plugs tell a story", you can find them online, or buy one and stick up in the garage.
Going on a trip with my 2015 road king. While checking everything the stock 6r12 plugs have about 10,000 on looked good but I had another set of fancy iridium plugs in the toolbox. Tossed them in and bike started better & idled better. Wasn’t even gonna change them but glad I did
My own experience on my 2007 Ultra I installed true duel exhaust, Vance and Hines mufflers, high intake air and with this a Fuel pack. I have found that between 6 to 10 thousand miles my check engine ligh comes on and takes longer to go off. When I change spark plugs this remedies the problem. Change Spark Plugs Spark!!!
I know it’s a 2 year old video but just wanted to add according to the service interval per manufacture specifications on my 15 Road Glide 103HO it’s replace spark plugs every 2 years/30,000 miles which ever comes first. Yes I strongly agree with you keep it simple what you take out is what you put back in .... unless your doing major engine modifications such as altering the compression, etc than it starts to matter.
Hi Doc I agree with you, especially for people changing their own. Better performance for less than the price of a value meal, why not? My only thing is my bike has NGK plugs and after talks to NGK they told me no anti-seize because their plugs already have a coating. So I would say check to see if your plugs have a coating before adding anti-seize, could cause you problems over torquing the plugs
My bike has 9k miles on it. Just added a S&S cam and a Vance and Hines exhaust. Been having a very hard time getting it tuned. Pulled the plugs and the gaps were closed (under .020) not sure how that happened but she runs much better with the proper gap
One additional comment to spark plug changing is to not over-tighten. It's easy to do. Best is to check the service manual and use a torque wrench. CAUTION: if you use anti-seize as Doc recommended, the torque value in the service manual DOES NOT APPLY. The torque values in the manual are for clean, dry threads with only the oil from manufacture. Anti-seize will cause much higher thread loads by the time the torque value on the wrench is met.
And ..with the extreme heat the anti seize can get down into your cylinder heads not a good thing.. I base this on car racing if you want your plugs to foul extreme temperatures put some anti seize on them
Good video. I notice many Harley riders spare little expense on their "babies". Most NEVER wait until the mileage specified in the maintenance chart, yet every other machine they own they won't replace a part until it breaks. The arguments that "plugs are cheap", "cheap insurance", "why not just replace them?" makes little sense. If a spark plug cannot last more than 2,000 miles, you bought a crap plug! In the video he refers to the fact that Harley has extended the mileage interval for spark plug replacement and that is for a good reason. "Doc Harley" states the plug is exactly the same. I cannot say with certainty that he is incorrect, but as an auto technician I know plugs have evolved immensely over the last few years. He is absolutely correct when he said the electrodes erode and the gap widens, but the metal which was used was steel or copper. THOSE plugs lasted 30,000 miles in a car. Today the mentality of plug design is to treat the 2 electrodes with platinum or iridium. These 2 precious metals are able to sustain much more abuse without wearing down. Sure, a 2 cylinder engine will fire the plug more often than my Dodge pick up V8, but come on, 2,000 miles!!!? I have much better things to do and remember than to change the Iridium plugs in my Dyna every 2,000 miles. If you're bored and want to "FIX" something on your scooter, check the tire pressure against factory recommended psi. I bet they need air.
Hey VN, when u take something (voltage) it's the same as receiving, Da. don't try to knock what this guy has to say. He takes the time, has the knowledge and his presentation is relaxed and positive. Thanks Doc.
Hey Doc Would you mind doing a video explaining the improvements made in the 2024 M8 engine, if any, regarding crankcase breathing and oil getting to the pistons, you’re knowledge, and advice is greatly appreciated
I normally change my spark plugs every 1500 miles or 2000 depending if I'm getting ready to head for bike week. I bought this little case that holds two spark plugs. I have three of them and when I change my plugs I put the old ones in this plastic case. That way if someone else riding with us has an issue I have spark plugs with us so we can get back to riding. The only stuff that I use on my bike is Harley-Davidson parts. I'm not going to name aftermarket brands that I try at the beginning when I purchased my first Harley. The parts that these aftermarket people sell just do not have the same quality that a Harley-Davidson part has. I use their spark plugs I use the oil when I change lights it's always Harley-Davidson. Great video a lot of people just do not think about their spark plugs. Even with the frequency of me changing my plugs I can feel a big difference the next time I ride my bike.
Thank you for sparkplug tips. My 103 has a stage one kit currently which has been tuned at Harley Davidson so I recently changed my sparkplugs on my 2015 Ultra Limited to Screaming Eagle sparkplugs and also upgraded my plug wires to the Screaming Eagle plug wires. Hoping for a little more performance until I go to the next stage 2 kit.
Doc Harley, One thing you did not discuss was resistor spark plugs. They have a built-in gap also in the ceramic stem. You can’t see that but that gap also wears down and gets round. I usually change mine every oil change. They’re not that expensive and I ain’t doing anything while I’m waiting for the oil to drain.
They are $4-$10 bucks each depending on brand and where you buy them. Personally I buy the HD silver and change mine with every oil change. But I also ride my bike almost every day, year round. Take care of your ride and it will last longer.
Good information. I change my plugs every 10K miles whether they need it or not. I think my service manual for my 2016 HD Streetglide Special says every 35K miles which makes no since.
Thanks Doc, any tips is good news. Have to go through your archival tips , if any, on the marvevllous V Rod. In particular the ' do I or don't I remove the air intake shroud ' dilemma. Cheers. Ed Queensland. Australia.
Thanks for the reply. I have read that through the removal of the V Rod air box it is possible to achieve a substantial horsepower increase. If so, my dilemma is how would one compensate for the loss of contaminent protection from dust particles that the current sealed system provides so adequately? The above insinuation seems to indicate that the current set-up restricts maximum air flow and hence a loss of power. Could you please throw some light on this theory.
Awesome video Doc. I have a question. I have a 2022 Harley Davidson XL883N Iron 883 and was wondering what brand or name of spark plug should I be using in my Iron 883 and what should be the gap?
Great advise... this video gives you great details on the basic spark plug install . .little steps in this video add up to the proper install . . . no more ' hick' ups'.... thank you
Hi Thanks for your interesting videos. How about iridium sparkplugs? My ECU is of S&S VFI, with knock detection mounted to the rear head. So no need for ION. What do tell about those plugs? Thanks Doc. Greetings Peder
Those spark plugs are made of the finest material. You have a rare system there. I have not had the pleasure to work with and understand everything about it. Have opinions but the choice is yours…..Doc
@@LowCountryHarleyDavidson Thanks mr Doc. Trial and error. I will at least try them. Thanks for your fast reply. Im living in Sweden. 🇸🇪 Will put the ride on a Dyno now at Tuesday. I have done a lot of changing on the fuel map. But you see S&S oxygen sensors are of the narrow band. They can not do its job. So now I have shut down the closed loop and the adaptiv maps. Dyno run is whats left. Auto tune even with wide band sensors, what I have learned, is they need dyno to to get the fine adjustment. My thoughts. Thanks again for your fine and tutorial videos. Greetings Peder 😊👍🏻😅🇸🇪🇺🇸
Great tip, with common sense. The good old school tune up: Plugs, Oil and Filters. I suppose we have done away with points by now but, My old 1980 FXRS80 had points.
So I have a 2012 FLHX Street Glide,does it only have 2 plugs the manual I was looking at said it has 4,remove the tank to get the other two ???? Thanks for your answer Sam
And do not go to hotter range spark plug tips if your riding style is mostly average speed with the usual blasts for kicks. Like the man said, the lower end of the OEM gap is better.
Great tip Doc. plus spark plugs (not talking about the ones that are hyped to boost your HP rating by 50%, or they are so intense they would ignite space shuttle fuel) are so inexpensive, would only make sense to put in new plugs even at 6 to 8 thousand miles. Your Harley's worth it!!!
Doc, I pu a 2003dyns wide glide with 50+kmiles. I am changing the plugs. But, should I also change the plug wires ? If so, what kind would you recommend? Thanks for your experienced help.you help us hd bike riders so much.
When I was in auto shop on high school (1000 years ago) I was assigned to rebuild an old Maytag GAS POWERED washing machine engine. The spark plug was dated 1918 and it was a fat little guy. Here's the big thing; it had a little 8-bladed fan on the bottom, NOT the typical spark-gap thing (I'm sure there's a name for it but I don't know what it is) like today. Have you ever seen a spark plug like that? BTW, I had to use it and it still worked like it was brand new!
Here's why I disagree with a 10,000 mile spark plug replacement. 1. Engines run closer to the stoichiometric A/F ratio, so plugs stay cleaner. 2. Modern engines have higher ignition voltage, making for a hotter spark and easier to jump the gap. 3. We no longer use lead in the fuel, and fuels are better than those of years past. 4. Engines are better built and have lower blow-by minimizing oil burn and resultant plug contamination. I change mine at 50,000 miles...never a hiccup.
I over looked changing my OEM spark plugs at just under 69K miles. I didn’t notice any performance issues on my then 110” 2015 CVO motor. I plan to change them at 20K miles from now on.
Iridium plugs have an anode and electrode so hard, they don't wear nearly as fast. Their gap stays constant. Also, torque down your plugs properly. My 1200 Sporty starts right up, cold or hot.
Doc....thank you for all your tutorial & how to video's. Spark plug question. 2012 Street Glide,stock 103, just turned 40k miles. I use the factory recommended plugs. On recent 40k service at dealership,tech showed me my 5k mileage plugs installed at 35k service) and very top of outer electrode (ground strap),had white deposit. Bike always ran and performed very well. Center electrode had normal wear,no build up. I changed fueling station,but kept using 93 octane. Tech said cylinders and piston tops look good. Any knowledge on why top of electrode had white deposit? Oil migration? (piston rings? valve stem seal /seats? head gasket?) Should I request a compression test on each cylinder? Is it too much to change plugs every 5k miles now that mileage on bike is climbing?
Hi doc ! Is it true when we re replacing the spark plug cable, for the 10mm cable on a M8, it's better to replaced the spark plug for screaming eagle performance or it's bulls... Thanks !
I'm watching this thinking about my car engine, way newer tech and way more power per cc than my HD. Changes the plugs every 10 yrs, car runs fine on cheap ethanol gas, get awesome mileage. I just put some iridium plugs in my bike though:) After 7.000 miles and the original ones looked fine.
@@LowCountryHarleyDavidson I apologize for making an observation and expressing my doubts as to whether or not a spark plug is worn out in such a short service life.
The reason they increased plug change intervals is the same reason they increased fluid change intervals. It reduces cost of ownership. I still recommend plugs @ 10k, engine oil @ 2500 and primary and trans fluid & 5k. Lubricant quality has improved over time so people argue “ it doesn’t break down as quickly” but changing oil is about removing contaminants more so than oil breakdown. Contaminants come from internal component wear and corrosive chemicals introduced from the combustion chamber.
Heres my advice to harley owners. Have a pouch or use your saddle bags and keep four new spark plugs and a ratchet and socket in any harley you use. When you start them cold and one cylinder doesnt fire until it runs for 10 seconds (which is common), change the plugs. Some will miss out and you have to keep reving them when theyre cold, change the plugs. For the record I have had the best luck with auto lite spark plugs. You have to cross reference them to know what size, as my twin cam uses a different size than my evos. Always also be sure to compare the reach of a plug with the old plug, because if your reach is longer you can knock a hole in a piston top or if too short can result in carbon. Also, keep a round plug gap tool on your key ring, so you can gap them
@@LowCountryHarleyDavidson Havent learned that much about the M8 yet though. But from what Ive seen I think the M8 version appears better mechanically than the TC B version due to gear to counter balancers instead of the guide and chain
You're taking about New Plugs and the Gaps. Took the plugs(Factory) out of my 2018 1200 Custom. Checked the gap. One cylinder was at .035. The other at .040. Only 200 miles on Odometer. Replaced them with a set of NGK Iridium. Found over the years the Iridium last longer. Ran a set of NGK in a Street 750. 10k Miles and no wear. NGK said not use Anti Seize. It affects the Ground. And the oil runs down the heat sink.
Hi DOC... Hows Things... I have Two Harley Davidson.... I have a 2002 H.D . Heritage Softail Classic FLSTC and a 2009 H.D. Super Glide FXD... Are the Spark Plugs Gap the same for Both Bikes... Also what would be the Best Gap and When Should They Be Done... (Every Two Years or 10,000 Miles)... I Don't get a chance to Ride them, But Want Them To Sound, Preform and Last a Long Time.... They were Original Plugs Still In Both... Bike 1)13,512mi, Bike 2)6,697mi.... Thank you, Frank
Doc I could not have said it any more clearly. Perfect, plus check your wires for being dried out and the boots over the plug. I alsways change them out at 10K but i use NGK and changed out to Harley Fat Wires. Tech tip...carry a spare set in your bags...what $15.00 to save headaches. No brainer
Trikes are the way to go ! I swore I would never ride anything EXCEPT an Electra Glide. I just bought a 2019 Freewheeler and I've never looked back. Motorcycling is fun again and I feel much safer. Especially with my lady on the back !
Not sure you’re correct on the anti seize torque statement. I twisted a wrench for Cummins, and antiseized every thing that I might see again some day. I always went by torque specs and never pulled a thread.
On an older Cummings 855 if you torqued the head bolts with never seize you could crack the counter bore. That's one of the reasons they came out with water passage inserts. Torque values only apply with the specified lube
Just to add I use either dbl platinum or iridium plugs because they last a longer in whines in good cond using little or no oil between oil changes. If your motors tired no plugs will last as long because of oil burning build up if carbon etc on the plugs causing you yo have to change them earlier.
Priceless information, as is your custom Sir. However, I was put off by the increased change interval HD recommendation…it should be shorter than 10K. If a 10K plugs is in such a condition that a simple visual inspection confirms, “definitely needs replacing” then it stands to reason, that a shorter interval is warranted. “PMS” in the U.S. Navy means, Preventive Maintenance System, the thought 💭 process is to KEEP equipment AT peak level performance while heading off failure. Doc, in my humble opinion PMS applied to HD spark plugs would suggest a 5K inspection and/or change. 2020 Fat Boy
I changed mine with OEM plugs from the dealer and air filter. I lost 40 miles to a tank of gas (5 gallons) in my ‘05 Heritage, changed around 43k miles. Should I have changed my plug wires, too? Weird that I had a pretty drastic mileage drop. One of the plugs I changed was even gapped wrong (small gap
great advice doc..question though.are thed V-fire electrode spark plugs or E3 electrode spark plugs make a difference.in your motors performance?thank you doc.
How about Not using spark plugs at all? TCB (Traction Controlled Braking) out of Texas making head gaskets with 4 spark igniter giving no loss of spark from plug (no plug puts a bolt in spark plug hole just to close it off) an better circular cylinder firing with 4 equally spaced computer controlled sparks, Very Cool! P.S. his braking system for motorcycle great too!
My 2019 Street Bob, with Vance & Hines Big Radius, Screaming Eagle Air Cleaner and SE Pro Street Tuner base Map with 6025 Miles, Bought it with 3000 2month ago at the Harley Dealership. it was first Bought in 2018... Any Suggestion when I should Change the Plugs? Thanks
Need advice. I have a 2006 custom sportster. I changed the plugs the other day. I started it up, no problem. I touched the rubber boot on the plugs with my finger and got shocked. I can’t imagine the wires are bad as they only have 1200 miles on them plus they weren’t bad before I touched them. Could I have done something wrong? I used Ngk iridium
First to check is the cap at the top of the spark plugs. Some are made to come off. Tighten if loose. Make sure plug wires are pushed in coil all the way. Mileage is low but 14 years of out in the weather can break down wires. I would replace them. ~ Doc
@@LowCountryHarleyDavidsonI have a 2017 ultra limited. I bought it with only 8600 miles. I use non ethanol gas in it. Do I need to change plugs now or wait? Thanks for the info.
I've read where plug manufacturers specifically state NOT to use anti seize on plug threads. I believe it had something to do with interfering with proper torque specs
Thanks for yet another helpful video!! I have a question I live in a cold weather climate and store my bike outdoors. I removed the battery from my Sportster 1200, so that the cold weather does not drain it. If I keep it indoors at room temp do you think I still need a trickle charger/battery tender? My gut tells me yes. What do you think?
I agree with your gut. The modern battery tender monitors the battery and keeps it in peak condition without overcharging. It will be ready for riding season 👍 Thanks ~ Doc
Daniel D & Doc, Food For Thought. Batteries stor best at temps. between 38 & 48° F. Your battery tender won't work as hard either.(Not that it's straining at room temp. ☺) For lead acid batteries the key is in the UN-Diluted Electrolyte. If you've added water to your battery then everything changes. My "battery charger" has a 1.5 Amp float cycle and a 3.0 Amp charge cycle. I don't need it often & it takes most of the night to charge a dead battery but my batteries last a long time and I haven't cooked the life out of one since I quit using 10+ Amp chargers. 🤷♂️
I have question about an 03 Harley Sportster 1200. How can i bypass the vacuum operated petcock for a manual petcock? Do I need to plug lines on the VOES or carb? Do I remove VOES or just leave it? Not sure if you would know how, but I appreciate any feedback.
I just bought a 91 Harley Sportster XLH 883 and it will foul the plugs within 10 miles black shut not wet why do you think the problem is I got a new carburetor I'm going to try
Just a few suggestions. Check intake manifold rubber seals for leaking. Stock spark plugs? Aftermarket can be wrong. Choke sticking on? Ignition coil weak? Stock carb or someone substituted a performance carb that is not jetted for the 883……Doc
I watched a video on screaming eagle spark plugs and wires and coil what’s your opinion DOC ? on Change stock to the screaming eagle on a 1200 custom Harley Davidson 2006?
Doc, just bought a 2019 FLDE, 489 miles. Last HD I purchased was a 04 super glide.
I find your maintenance videos very helpful with sincerity & honesty.
It appears you have a lot of experience & wisdom on HD motors new & older models
Thanks for all the assistance & advice.
Congratulations on your find. We appreciate your time watching our videos and posting kind words….Doc
I just changed plugs and wires yesterday. I went with stock plugs and Symax 8mm red wires. My 96 ci 07 FXSTC has a Stage 1 mod. I gapped the plugs to 38 as Doc recommended. Test ride was AWESOME. She definitely runs better and responded quicker. The plugs I pulled were about 43 so at the max gap. Thanks Doc for YOUR infinite wisdom!
I own an aftermarket shop...this guy is just good, I have my customers go to youtube while we are working on their bike.Plus he is articulate.
Doc, I know that I am a bit late to everything. I have a 03 fat boy. So I am new . I love it as everyone else does. I want to thank you for your videos. You are giving me a ton of information. No way can I ever thank you enough Sir!!!
Thank you for your support Dale....Doc
NGK spark plugs feature what is known as ‘trivalent plating’. This is a silver-or-chrome coloured finish on the threads that is designed to provide corrosion resistance against moisture, chemicals and weathering. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage
Thank you for sharing this important information. I am concerned about steal going into aluminum without lube🤷♂️…Doc
It's not a bad idea to have some antiseize compound on the thread of the sparkplug, but you have to compensate for the torque-value. This is a good advice you gave. Thank you for sharing your experience and background story. 👍👍👍👍👍. Greetings from The Netherlands
Your dad sounds like a smart man, he taught you well. Now you get to teach us a thing or two about Harleys. Great video Doc, see you next time!
Thanks 👍
It amazes me how many people don't know how to do simple maintenance. Thanks for helping the world be a little bit more aware of proper care of their scooters
When I first looked at the title I said, “Yeah, why change them”. I learned something!
Going to get spark plugs from the dealership right now thank you for sound advice and taking the time out to do these videos they greatly help us who aren't professional mechanics but can at least do minor repairs and upgrades
Thank you Doc, I was getting tired of different dealerships telling that it's normal on a 2 month old bike. 2021 streetbob with 8200 miles on.
Great info. Thanks. Don't forget about the crush washer, needs replaced when you dress the plug and adjust the gap if you reuse the same plug.
When you change your front tire change your spark plugs too.Thanks for the information, it's right on.
Russell Linthicum this is true. I just bought a 2005 Sportster, with 11,000 miles on the clock, on the original front tyre. I’ve just replaced the tyre and the plugs too. Not too sure whether 15 years is a very good service interval though. 🙂
Thanks Doc! Perfect timing, I’m changing my plugs on my Iron 883 this week 👍👍
NGK, gapped at .040, change every 5000 miles. Cant go wrong.
There is nothing better than the stock oem plugs. But if I can’t get them, then ngk.
Good info .Spark plugs can be cleaned and gap can adjusted. Riding for over 25 years. Plugs have never been a problem. I only had one ever fail completely. A little maintenance goes a long way .
.
Great point....Doc
As always, Doc, you are awesome. You make it seem so clear and sensible when you explain issues.
I appreciate that....Doc
My Ultra Limited was getting hard to start at 14,000+ miles. Initially thought it was the battery as it is the original battery on a 2016. Decided to put in new plugs and what a difference. Bike fires right up and the power on the road is back. I didn’t realize the amount of power loss the old plugs were causing. I’m going to go with Doc’s advice and replace the every 10,000 miles from here on out.
Check plug tops, make sure they are tight. Anti seize threads, and a little dielectric grease on plug top and a little in the boot for ease of slip on. Champion Spark Plug Chart shows you how "Spark plugs tell a story", you can find them online, or buy one and stick up in the garage.
A good follow up Tech Tip….Doc
Going on a trip with my 2015 road king. While checking everything the stock 6r12 plugs have about 10,000 on looked good but I had another set of fancy iridium plugs in the toolbox. Tossed them in and bike started better & idled better. Wasn’t even gonna change them but glad I did
My own experience on my 2007 Ultra I installed true duel exhaust, Vance and Hines mufflers, high intake air and with this a Fuel pack. I have found that between 6 to 10 thousand miles my check engine ligh comes on and takes longer to go off. When I change spark plugs this remedies the problem. Change Spark Plugs Spark!!!
I know it’s a 2 year old video but just wanted to add according to the service interval per manufacture specifications on my 15 Road Glide 103HO it’s replace spark plugs every 2 years/30,000 miles which ever comes first. Yes I strongly agree with you keep it simple what you take out is what you put back in .... unless your doing major engine modifications such as altering the compression, etc than it starts to matter.
Hi Doc I agree with you, especially for people changing their own. Better performance for less than the price of a value meal, why not? My only thing is my bike has NGK plugs and after talks to NGK they told me no anti-seize because their plugs already have a coating. So I would say check to see if your plugs have a coating before adding anti-seize, could cause you problems over torquing the plugs
Doc, thanks so much! My bike has had a hiccup every once in a while lately. I’m checking the spark plug when I get home
and survey said ?
My bike has 9k miles on it. Just added a S&S cam and a Vance and Hines exhaust. Been having a very hard time getting it tuned. Pulled the plugs and the gaps were closed (under .020) not sure how that happened but she runs much better with the proper gap
One additional comment to spark plug changing is to not over-tighten. It's easy to do. Best is to check the service manual and use a torque wrench. CAUTION: if you use anti-seize as Doc recommended, the torque value in the service manual DOES NOT APPLY. The torque values in the manual are for clean, dry threads with only the oil from manufacture. Anti-seize will cause much higher thread loads by the time the torque value on the wrench is met.
And ..with the extreme heat the anti seize can get down into your cylinder heads not a good thing.. I base this on car racing if you want your plugs to foul extreme temperatures put some anti seize on them
Good video. I notice many Harley riders spare little expense on their "babies". Most NEVER wait until the mileage specified in the maintenance chart, yet every other machine they own they won't replace a part until it breaks. The arguments that "plugs are cheap", "cheap insurance", "why not just replace them?" makes little sense. If a spark plug cannot last more than 2,000 miles, you bought a crap plug!
In the video he refers to the fact that Harley has extended the mileage interval for spark plug replacement and that is for a good reason. "Doc Harley" states the plug is exactly the same. I cannot say with certainty that he is incorrect, but as an auto technician I know plugs have evolved immensely over the last few years. He is absolutely correct when he said the electrodes erode and the gap widens, but the metal which was used was steel or copper. THOSE plugs lasted 30,000 miles in a car. Today the mentality of plug design is to treat the 2 electrodes with platinum or iridium. These 2 precious metals are able to sustain much more abuse without wearing down. Sure, a 2 cylinder engine will fire the plug more often than my Dodge pick up V8, but come on, 2,000 miles!!!? I have much better things to do and remember than to change the Iridium plugs in my Dyna every 2,000 miles. If you're bored and want to "FIX" something on your scooter, check the tire pressure against factory recommended psi. I bet they need air.
He didn’t say change them every 2000 miles........he said 10,000 miles, big difference.
Hey VN, when u take something (voltage) it's the same as receiving, Da. don't try to knock what this guy has to say. He takes the time, has the knowledge and his presentation is relaxed and positive. Thanks Doc.
Hey Doc
Would you mind doing a video explaining the improvements made in the 2024 M8 engine, if any, regarding crankcase breathing and oil getting to the pistons, you’re knowledge, and advice is greatly appreciated
I normally change my spark plugs every 1500 miles or 2000 depending if I'm getting ready to head for bike week. I bought this little case that holds two spark plugs. I have three of them and when I change my plugs I put the old ones in this plastic case. That way if someone else riding with us has an issue I have spark plugs with us so we can get back to riding. The only stuff that I use on my bike is Harley-Davidson parts. I'm not going to name aftermarket brands that I try at the beginning when I purchased my first Harley. The parts that these aftermarket people sell just do not have the same quality that a Harley-Davidson part has. I use their spark plugs I use the oil when I change lights it's always Harley-Davidson.
Great video a lot of people just do not think about their spark plugs. Even with the frequency of me changing my plugs I can feel a big difference the next time I ride my bike.
can you tell me where HD. makes their oil ? I don't think so.
Thank you for sparkplug tips. My 103 has a stage one kit currently which has been tuned at Harley Davidson so I recently changed my sparkplugs on my 2015 Ultra Limited to Screaming Eagle sparkplugs and also upgraded my plug wires to the Screaming Eagle plug wires. Hoping for a little more performance until I go to the next stage 2 kit.
Doc Harley, One thing you did not discuss was resistor spark plugs. They have a built-in gap also in the ceramic stem. You can’t see that but that gap also wears down and gets round. I usually change mine every oil change. They’re not that expensive and I ain’t doing anything while I’m waiting for the oil to drain.
Correct flame kernel without straining secondary windings is key! Good one Doc! ✌🏻
I really don't understand what you're saying could you expand on that
They are $4-$10 bucks each depending on brand and where you buy them. Personally I buy the HD silver and change mine with every oil change. But I also ride my bike almost every day, year round. Take care of your ride and it will last longer.
I was considering getting a more expensive plug but I will take your advice.
Thanks for watching Mike….Doc
Yes sir great tip . I change mine every year at beginning of the riding season .... I live in the north ....lol
Yep do the spark plug replacement at every oil/filter change too 👍
Good information. I change my plugs every 10K miles whether they need it or not. I think my service manual for my 2016 HD Streetglide Special says every 35K miles which makes no since.
Wow! Got me thinking, 35,000 miles and don’t remember ever having them changes. Thanks
Jesus
Keep up the great work on all these videos Doc!!! Great feedback, we appreciate you boss 🫡
Thanks Doc, any tips is good news.
Have to go through your archival tips , if any, on the marvevllous V Rod.
In particular the ' do I or don't I remove the air intake shroud ' dilemma.
Cheers. Ed Queensland. Australia.
I am lacking in the V-Rod videos. If you have any suggestions please send to my Email…..Doc
Thanks for the reply. I have read that through the removal of the V Rod air box it is possible to achieve a substantial horsepower increase.
If so, my dilemma is how would one compensate for the loss of contaminent protection from dust particles that the current sealed system provides so adequately?
The above insinuation seems to indicate that the current set-up restricts maximum air flow and hence a loss of power. Could you please throw some light on this theory.
Excellent explanations Doc! That'll keep it runnin right. 👊
hello doc !!what about indexing spark plugs,
Loved performing this when racing but for the street🤷♂️…..Doc
Awesome video Doc. I have a question. I have a 2022 Harley Davidson XL883N Iron 883 and was wondering what brand or name of spark plug should I be using in my Iron 883 and what should be the gap?
Go to your local dealer and buy genuine HD Spark plugs. Gap .038-.042….Doc
Doc your old man was a smart dude. Thanks again doc
i change plugs every fall when i put the bike away for winter (OHIO) along with all
three hole of oil....put on about 6K a year....good insurance...
Great advise... this video gives you great details on the basic spark plug install . .little steps in this video add up to the proper install . . . no more ' hick' ups'.... thank you
Hi Thanks for your interesting videos. How about iridium sparkplugs? My ECU is of S&S VFI, with knock detection mounted to the rear head. So no need for ION. What do tell about those plugs? Thanks Doc. Greetings Peder
Those spark plugs are made of the finest material. You have a rare system there. I have not had the pleasure to work with and understand everything about it. Have opinions but the choice is yours…..Doc
@@LowCountryHarleyDavidson Thanks mr Doc. Trial and error. I will at least try them. Thanks for your fast reply. Im living in Sweden. 🇸🇪 Will put the ride on a Dyno now at Tuesday. I have done a lot of changing on the fuel map. But you see S&S oxygen sensors are of the narrow band. They can not do its job. So now I have shut down the closed loop and the adaptiv maps. Dyno run is whats left. Auto tune even with wide band sensors, what I have learned, is they need dyno to to get the fine adjustment. My thoughts. Thanks again for your fine and tutorial videos. Greetings Peder 😊👍🏻😅🇸🇪🇺🇸
Great tip, with common sense. The good old school tune up: Plugs, Oil and Filters. I suppose we have done away with points by now but, My old 1980 FXRS80 had points.
So I have a 2012 FLHX Street Glide,does it only have 2 plugs the manual I was looking at said it has 4,remove the tank to get the other two ????
Thanks for your answer
Sam
Your year has a Twin Cam motor with just 2 spark plugs. You have the wrong manual…..Doc
And do not go to hotter range spark plug tips if your riding style is mostly average speed with the usual blasts for kicks. Like the man said, the lower end of the OEM gap is better.
Great tip Doc. plus spark plugs (not talking about the ones that are hyped to boost your HP rating by 50%, or they are so intense they would ignite space shuttle fuel) are so inexpensive, would only make sense to put in new plugs even at 6 to 8 thousand miles. Your Harley's worth it!!!
Doc, I pu a 2003dyns wide glide with 50+kmiles. I am changing the plugs. But, should I also change the plug wires ? If so, what kind would you recommend?
Thanks for your experienced help.you help us hd bike riders so much.
Yes, If your bike is carb go with Magnacore or Taylor if your bike is fuel injected go with HD factory...Doc
@@LowCountryHarleyDavidson thanks again doc.
You are very logical and dead on accurate
I have a 2015 Limited Low. The owners manual says change every two years or 30k miles, whichever comes first.
When I was in auto shop on high school (1000 years ago) I was assigned to rebuild an old Maytag GAS POWERED washing machine engine. The spark plug was dated 1918 and it was a fat little guy. Here's the big thing; it had a little 8-bladed fan on the bottom, NOT the typical spark-gap thing (I'm sure there's a name for it but I don't know what it is) like today. Have you ever seen a spark plug like that? BTW, I had to use it and it still worked like it was brand new!
Thanks for sharing. I have a few unique spark plugs but none with a fan…Doc
may I add one thing to this. When you change your plugs use a torque wrench and set them to the proper torque.
and Use anti seize on every spark plug
My service manual says change at 20K - My dyna is at 10K right now. I suppose I should check/change my plugs based on this video. Thanks Doc.
Here's why I disagree with a 10,000 mile spark plug replacement.
1. Engines run closer to the stoichiometric A/F ratio, so plugs stay cleaner.
2. Modern engines have higher ignition voltage, making for a hotter spark and easier to jump the gap.
3. We no longer use lead in the fuel, and fuels are better than those of years past.
4. Engines are better built and have lower blow-by minimizing oil burn and resultant plug contamination.
I change mine at 50,000 miles...never a hiccup.
I over looked changing my OEM spark plugs at just under 69K miles. I didn’t notice any performance issues on my then 110” 2015 CVO motor. I plan to change them at 20K miles from now on.
Agreed ,for all you young guys out there ,try starting a kick start 6 volt
FL Panhead with bad plugs .
Been there, got the T-shirt and larger right calf.....Doc
Iridium plugs have an anode and electrode so hard, they don't wear nearly as fast. Their gap stays constant. Also, torque down your plugs properly. My 1200 Sporty starts right up, cold or hot.
Thanks for sharing your experience….Doc
I have to say. Doc makes a lot of sense.
Doc....thank you for all your tutorial & how to video's.
Spark plug question. 2012 Street Glide,stock 103, just turned 40k miles.
I use the factory recommended plugs.
On recent 40k service at dealership,tech showed me my 5k mileage plugs installed at 35k service) and very top of outer electrode (ground strap),had white deposit.
Bike always ran and performed very well. Center electrode had normal wear,no build up. I changed fueling station,but kept using 93 octane. Tech said cylinders and piston tops look good.
Any knowledge on why top of electrode had white deposit? Oil migration? (piston rings? valve stem seal /seats? head gasket?) Should I request a compression test on each cylinder?
Is it too much to change plugs every 5k miles now that mileage on bike is climbing?
Hi doc ! Is it true when we re replacing the spark plug cable, for the 10mm cable on a M8, it's better to replaced the spark plug for screaming eagle performance or it's bulls...
Thanks !
Bull…..Doc
I'm watching this thinking about my car engine, way newer tech and way more power per cc than my HD.
Changes the plugs every 10 yrs, car runs fine on cheap ethanol gas, get awesome mileage.
I just put some iridium plugs in my bike though:) After 7.000 miles and the original ones looked fine.
Well, maybe I should take this video down 🤔. Your facts are outstanding…..Doc
@@LowCountryHarleyDavidson I apologize for making an observation and expressing my doubts as to whether or not a spark plug is worn out in such a short service life.
The reason they increased plug change intervals is the same reason they increased fluid change intervals.
It reduces cost of ownership.
I still recommend plugs @ 10k, engine oil @ 2500 and primary and trans fluid & 5k.
Lubricant quality has improved over time so people argue “ it doesn’t break down as quickly” but changing oil is about removing contaminants more so than oil breakdown. Contaminants come from internal component wear and corrosive chemicals introduced from the combustion chamber.
Heres my advice to harley owners. Have a pouch or use your saddle bags and keep four new spark plugs and a ratchet and socket in any harley you use. When you start them cold and one cylinder doesnt fire until it runs for 10 seconds (which is common), change the plugs. Some will miss out and you have to keep reving them when theyre cold, change the plugs. For the record I have had the best luck with auto lite spark plugs. You have to cross reference them to know what size, as my twin cam uses a different size than my evos. Always also be sure to compare the reach of a plug with the old plug, because if your reach is longer you can knock a hole in a piston top or if too short can result in carbon. Also, keep a round plug gap tool on your key ring, so you can gap them
Earl it sounds like you could write a book on the knowledge you have gathered over the years of riding. Thanks for sharing..Doc
@@LowCountryHarleyDavidson Havent learned that much about the M8 yet though. But from what Ive seen I think the M8 version appears better mechanically than the TC B version due to gear to counter balancers instead of the guide and chain
Excellent... Thank you sir 👍🏾
He's like the Alton Brown of Harleys
Spot on dude
You're taking about New Plugs and the Gaps. Took the plugs(Factory) out of my 2018 1200 Custom. Checked the gap. One cylinder was at .035. The other at .040. Only 200 miles on Odometer. Replaced them with a set of NGK Iridium. Found over the years the Iridium last longer. Ran a set of NGK in a Street 750. 10k Miles and no wear. NGK said not use Anti Seize. It affects the Ground. And the oil runs down the heat sink.
Hi DOC... Hows Things... I have Two Harley Davidson.... I have a 2002 H.D . Heritage Softail Classic FLSTC and a 2009 H.D. Super Glide FXD... Are the Spark Plugs Gap the same for Both Bikes... Also what would be the Best Gap and When Should They Be Done... (Every Two Years or 10,000 Miles)... I Don't get a chance to Ride them, But Want Them To Sound, Preform and Last a Long Time.... They were Original Plugs Still In Both...
Bike 1)13,512mi,
Bike 2)6,697mi....
Thank you, Frank
Doc I could not have said it any more clearly. Perfect, plus check your wires for being dried out and the boots over the plug. I alsways change them out at 10K but i use NGK and changed out to Harley Fat Wires. Tech tip...carry a spare set in your bags...what $15.00 to save headaches. No brainer
Thanks Doc I have a 2019 triglide the reverse stopped and I watched your video and reset the breaker it works fine thanks Joe in Valdosta Ga.
Trikes are the way to go ! I swore I would never ride anything EXCEPT an Electra Glide. I just bought a 2019 Freewheeler and I've never looked back. Motorcycling is fun again and I feel much safer. Especially with my lady on the back !
I change my plugs every spring then halfway through the riding season, 2 oil changes @ 3500 miles each.
Wow……Doc
Not sure you’re correct on the anti seize torque statement. I twisted a wrench for Cummins, and antiseized every thing that I might see again some day. I always went by torque specs and never pulled a thread.
I drop the torque value by 5 -10 with anti-sneeze.... done it for years on cars, truck & tractor engines and Never fouled a plug with anti-sneeze...
On an older Cummings 855 if you torqued the head bolts with never seize you could crack the counter bore. That's one of the reasons they came out with water passage inserts. Torque values only apply with the specified lube
Doc, thank you for your video. They are an excellent source of sound advice. Keep them coming.
Just to add I use either dbl platinum or iridium plugs because they last a longer in whines in good cond using little or no oil between oil changes. If your motors tired no plugs will last as long because of oil burning build up if carbon etc on the plugs causing you yo have to change them earlier.
Thanks for the Tech Tip....Doc
Priceless information, as is your custom Sir. However, I was put off by the increased change interval HD recommendation…it should be shorter than 10K. If a 10K plugs is in such a condition that a simple visual inspection confirms, “definitely needs replacing” then it stands to reason, that a shorter interval is warranted. “PMS” in the U.S. Navy means, Preventive Maintenance System, the thought 💭 process is to KEEP equipment AT peak level performance while heading off failure. Doc, in my humble opinion PMS applied to HD spark plugs would suggest a 5K inspection and/or change. 2020 Fat Boy
You are so correct....Doc
I changed mine with OEM plugs from the dealer and air filter. I lost 40 miles to a tank of gas (5 gallons) in my ‘05 Heritage, changed around 43k miles. Should I have changed my plug wires, too? Weird that I had a pretty drastic mileage drop. One of the plugs I changed was even gapped wrong (small gap
Agree, weird that you had a pretty drastic mileage drop. There has to be more to the story...Doc
Great video and advice. Plugs every 10k miles is cheap insurance. Use the OEM plugs.
Doc Holiday dude is cool 😎👍🏼🏍
Great tips !
great advice doc..question though.are thed V-fire electrode spark plugs or E3 electrode spark plugs make a difference.in your motors performance?thank you doc.
I do not have enough experience using these products to recommend.....Doc
Great advice.
What's your explanation for Harley Davidson lengthening times between plug changes? It's sure not for saving customers money.
I don’t know. I am guessing the better combustion chamber, fueling/ignition curve and dual plugs in the M8
How about Not using spark plugs at all? TCB (Traction Controlled Braking) out of Texas making head gaskets with 4 spark igniter giving no loss of spark from plug (no plug puts a bolt in spark plug hole just to close it off) an better circular cylinder firing with 4 equally spaced computer controlled sparks, Very Cool! P.S. his braking system for motorcycle great too!
My 2019 Street Bob, with Vance & Hines Big Radius, Screaming Eagle Air Cleaner and SE Pro Street Tuner base Map with 6025 Miles, Bought it with 3000 2month ago at the Harley Dealership. it was first Bought in 2018... Any Suggestion when I should Change the Plugs? Thanks
Take a look at left side spark plugs at 10K. Then make the decision..Doc
grate advice .. spark plugs are so overlooked now days.
Love your videos… 🔥🔥🔥changing mine this week jus hit 10k
Need advice. I have a 2006 custom sportster. I changed the plugs the other day. I started it up, no problem. I touched the rubber boot on the plugs with my finger and got shocked. I can’t imagine the wires are bad as they only have 1200 miles on them plus they weren’t bad before I touched them. Could I have done something wrong? I used Ngk iridium
First to check is the cap at the top of the spark plugs. Some are made to come off. Tighten if loose. Make sure plug wires are pushed in coil all the way. Mileage is low but 14 years of out in the weather can break down wires. I would replace them. ~ Doc
Low Country Harley-Davidson thank u. I’ll do that
my M8 service interval state 30k or every two years. I understand mileage, but why the time interval ?
Can only guess, a very low mileage bike sitting with this ethanol fuel deposits can’t be good….Doc
@@LowCountryHarleyDavidsonI have a 2017 ultra limited. I bought it with only 8600 miles. I use non ethanol gas in it. Do I need to change plugs now or wait? Thanks for the info.
I've read where plug manufacturers specifically state NOT to use anti seize on plug threads. I believe it had something to do with interfering with proper torque specs
I need to find this. I can’t believe putting steal threads into aluminum heads doesn’t need some kind of lubricant….Doc
Doc, I can't Find the gap. Spec for replacement plugs in my service manual. Where do I get that information?
Thanks for your help sir.
Thanks for yet another helpful video!! I have a question I live in a cold weather climate and store my bike outdoors. I removed the battery from my Sportster 1200, so that the cold weather does not drain it. If I keep it indoors at room temp do you think I still need a trickle charger/battery tender? My gut tells me yes. What do you think?
I agree with your gut. The modern battery tender monitors the battery and keeps it in peak condition without overcharging. It will be ready for riding season 👍 Thanks ~ Doc
@@LowCountryHarleyDavidson
I'm going with you and my gut then!!
Thanks Doc!!
Daniel D & Doc, Food For Thought.
Batteries stor best at temps. between 38 & 48° F. Your battery tender won't work as hard either.(Not that it's straining at room temp. ☺)
For lead acid batteries the key is in the UN-Diluted Electrolyte. If you've added water to your battery then everything changes.
My "battery charger" has a 1.5 Amp float cycle and a 3.0 Amp charge cycle. I don't need it often & it takes most of the night to charge a dead battery but my batteries last a long time and I haven't cooked the life out of one since I quit using 10+ Amp chargers. 🤷♂️
I have question about an 03 Harley Sportster 1200. How can i bypass the vacuum operated petcock for a manual petcock? Do I need to plug lines on the VOES or carb? Do I remove VOES or just leave it? Not sure if you would know how, but I appreciate any feedback.
Please keep your VOES. Use on of the existing hoses to go from the carb to the VOES. Eliminating the "T" to the original fuel valve.
I just bought a 91 Harley Sportster XLH 883 and it will foul the plugs within 10 miles black shut not wet why do you think the problem is I got a new carburetor I'm going to try
Just a few suggestions. Check intake manifold rubber seals for leaking.
Stock spark plugs? Aftermarket can be wrong. Choke sticking on? Ignition coil weak? Stock carb or someone substituted a performance carb that is not jetted for the 883……Doc
Thanks sir
Welcome...Doc
What is the proper torque specification to torque the spark plug down to
There is a reason I don’t quote torque specks. A Harley-Davidson 45 is greatly different than a M8…..Doc
@@LowCountryHarleyDavidson Thank you for the reply Doc. I have a 09 Road king with a 96 CID engine. Hope your day is good Sir.
Thank you for the great videos. Can you do one on installing a charging port on the handle bars for a cell phone?
Nice idea. What model were you thinking about?....Doc
@@LowCountryHarleyDavidson on a 2015 Road King Put a charging port up on the handlebars by my cell phone holder.
My bike isn't at 10000 miles yet but plugs are rusty, so should I clean them or replace them?
If my bike starts up at 750 rpm and slowly gets to 1000 rpm and stalls when I hit the the clutch and stop at a light could that be spark plug ?
Part of it because your intake seals have gone bad so the wrong amount of fuel is dumping on them….Doc
I watched a video on screaming eagle spark plugs and wires and coil what’s your opinion DOC ? on
Change stock to the screaming eagle on a 1200 custom Harley Davidson 2006?
Good monning Doc-Harley 👍. Have a blessday. 👀👂
We appreciate the blessing....Doc