Spark plugs

[Alan neill]

At what mileage are you changing the four spark plugs or are you doing every two three years not much talk about them

 

[Keehn]

I don't think anyone's gotten enough mileage yet to worry about the plugs?

I may be wrong, but as for me, plugs are a change as needed, not change on a schedule item, unlike oil.

Mike

 

[Ulrich]

@ 10 000 miles give or take a few for me ... I am about to change mine when I do the 10 000mile valve check. Got them out at the time anyway ... so I may as well


EDIT: I usually keep the old ones as emergency spares ... if they still look good

EDIT2: 4??? sorry I only have 2

EDIT3: NM I guess there are 4 ... what an odd place to put the other 2 on the bottom ... I totally missed that ... sigh

 

[David R]

23,000 on original R18.

I will keep them until I can find a reason to replace them.

over 50,000 on the last set (4) I put in my R1200R.

Its like the effin gear oil. Lesser quality plugs last 100,000 miles in vehicles all the time. There is no lead in the gas.

I "rotate" my plugs every valve check, bottom to top. Both bikes.

David

It has used no oil.

 

[Keehn]

@ 10 000 miles give or take a few for me ... I am about to change mine when I do the 10 000mile valve check. Got them out at the time anyway ... so I may as well


EDIT: I usually keep the old ones as emergency spares ... if they still look good

EDIT2: 4??? sorry I only have 2

EDIT3: NM I guess there are 4 ... what an odd place to put the other 2 on the bottom ... I totally missed that ... sigh

Ulrich, you swap your plugs out at 10k miles?!?! Are you running an airplane engine!!! j/k

Pump gas nowadays doesn't burn up plugs with properly tuned injectors like the carburetors of old. Even then, it was still possible to clean plugs that weren't damaged.

And yeah, our boxers are "Twin-spark" engines. The second plug is there apparently to burn the excess fuel that would have escaped out the exhaust pipe; a pseudo "emissions" control system of sorts, so BMW claims. But also the twin spark is also supposed to fix surging issues by ensuring complete combustion of fuel vapors in the chamber.

An aside: Twin spark and more are also used in aviation as redundant plugs, as well to prevent detonation with the leaded aviation fuel (yes...they STILL use leaded pump fuel at the airport/air strip for prop planes...)

https://www.bmwbmw.org/forums/viewtopic.php?f=14&t=11485
https://www.advrider.com/f/threads/what-is-twin-spark.432475/
https://www.motorbikestoday.com/news/Articles/BMW%20ignition.htm

Mike

 

[Ulrich]

Ulrich, you swap your plugs out at 10k miles?!?! Are you running an airplane engine!!! j/k

Pump gas nowadays doesn't burn up plugs with properly tuned injectors like the carburetors of old. Even then, it was still possible to clean plugs that weren't damaged.

And yeah, our boxers are "Twin-spark" engines. The second plug is there apparently to burn the excess fuel that would have escaped out the exhaust pipe; a pseudo "emissions" control system of sorts, so BMW claims. But also the twin spark is also supposed to fix surging issues by ensuring complete combustion of fuel vapors in the chamber.

An aside: Twin spark and more are also used in aviation as redundant plugs, as well to prevent detonation with the leaded aviation fuel (yes...they STILL use leaded pump fuel at the airport/air strip for prop planes...)

https://www.bmwbmw.org/forums/viewtopic.php?f=14&t=11485
https://www.advrider.com/f/threads/what-is-twin-spark.432475/
https://www.motorbikestoday.com/news/Articles/BMW%20ignition.htm

Mike

LOL ... this is my first 'modern' engine! ... with my Shovelhead I wouldn't leave home with a set of spares (and a spare set of points!) and a wrench with me ... I am still getting used to this

 

[Anibal]

Very interesting video

 

[Alan neill]

@ 10 000 miles give or take a few for me ... I am about to change mine when I do the 10 000mile valve check. Got them out at the time anyway ... so I may as well


EDIT: I usually keep the old ones as emergency spares ... if they still look good

EDIT2: 4??? sorry I only have 2

EDIT3: NM I guess there are 4 ... what an odd place to put the other 2 on the bottom ... I totally missed that ... sigh

Reason I was asking work on cars some plug changes are 60000 miles and if you change them at that interval they don't like coming out 10000 miles will do me as well thanks

 

[Ulrich]

Reason I was asking work on cars some plug changes are 60000 miles and if you change them at that interval they don't like coming out 10000 miles will do me as well thanks

Well I have to redo my whole thinking The BMW maintenance schedule calls for every 20 000 miles and I know that is (IMO) overly conservative knowing BMW ... so I think I go longer then and just check them every 10 000

 

[Keehn]

Well I have to redo my whole thinking The BMW maintenance schedule calls for every 20 000 miles and I know that is (IMO) overly conservative knowing BMW ... so I think I go longer then and just check them every 10 000

Okay...so this is getting ridiculous (currently researching my owners manual and google)...

The spark plug that BMW calls for is the "NGK MAR8AI-10DS" which is an Iridium-tipped plug. Anyone who's worked on cars knows that Iridium are practically the BEST kind of plugs you can get for longevity - they just don't wear out!

And yet, my Transcontinental manual wants me to REPLACE my IRIDIUM, yes...IRIDIUM spark plugs every 12k miles?!?!?! Are you "F"'ing kidding me!!!! Uhhhh....NO, I won't be doing that!

What I'll be doing instead is busting out my Fluke and doing ohmmeter checks on all four plugs. And, if all plugs check out at proper resistance spec, they'll go right back in Alcina! The "F"'ing WASTE in $$$

Sorry, I'm ranting here, but BMW is essentially asking us to throw out fine china to replace it with more fine china when there's nothing wrong with the original set. At 12k miles, Iridium plugs aren't even broken in yet! And this isn't a Japanese liter-bike, it's a low-RPM big boxer, so the plugs are seeing automobile-equivalent duty cycles ('ish).

I know that didn't help you at all Ulrich, but know that at least your shiny boxer has some super-strong Iridiums sparking the fuel inside the cans

Mike

 

[Ulrich]

Okay...so this is getting ridiculous (currently researching my owners manual and google)...

The spark plug that BMW calls for is the "NGK MAR8AI-10DS" which is an Iridium-tipped plug. Anyone who's worked on cars knows that Iridium are practically the BEST kind of plugs you can get for longevity - they just don't wear out!

And yet, my Transcontinental manual wants me to REPLACE my IRIDIUM, yes...IRIDIUM spark plugs every 12k miles?!?!?! Are you "F"'ing kidding me!!!! Uhhhh....NO, I won't be doing that!

What I'll be doing instead is busting out my Fluke and doing ohmmeter checks on all four plugs. And, if all plugs check out at proper resistance spec, they'll go right back in Alcina! The "F"'ing WASTE in $$$

Sorry, I'm ranting here, but BMW is essentially asking us to throw out fine china to replace it with more fine china when there's nothing wrong with the original set. At 12k miles, Iridium plugs aren't even broken in yet! And this isn't a Japanese liter-bike, it's a low-RPM big boxer, so the plugs are seeing automobile-equivalent duty cycles ('ish).

I know that didn't help you at all Ulrich, but know that at least your shiny boxer has some super-strong Iridiums sparking the fuel inside the cans

Mike

It did help ... btw. my R18 schedule calls for 20 000 (see the maintenance compilation that Scott made), but I am with you ... if it ain't broke don't fix it!!! and yes, it seems BMW is sure out to siphon as much coin as possible from folks that purchased their equipment ... I am not very fond of it! I bought this bike to outlive me ... but not at a cost (of maintenance) that I could have bought a couple other new bikes for

 

[Pork Rind]

It did help ... btw. my R18 schedule calls for 20 000 (see the maintenance compilation that Scott made), but I am with you ... if it ain't broke don't fix it!!! and yes, it seems BMW is sure out to siphon as much coin as possible from folks that purchased their equipment ... I am not very fond of it! I bought this bike to outlive me ... but not at a cost (of maintenance) that I could have bought a couple other new bikes for

My sentiments, exactly.... I never short out on new plugs for my Rotax 912 ULS in my airplane, and that's 1365 cc's with twin Bing 36 or 40 mm carbs running constantly at 5200-5500 rpm at 4.5 to 5.2 gallons of fuel per hour. I set the gap at .026" and in 400 hours, being checked annually, and treating the thread with heat sink paste, they've never gotten stuck in the motor, if torqued properly. I changed them at 400 hour, only because doing the annual I had them out and had already bought a new set, and they weren't even iridium. Iriidum plugs have gone 100,000 miles + in Ford Explorer V8's. The original plugs (two per cylinder) definitely give a more efficient burn and more HP than a single spark plug, more of the fuel air mixture gets burnt during combustion making power, as a result. A Mag check with rpm drop will confirm that, with motor under moderate load.

BMW is pretty blatant about their money grab, for those with any mechanical aptitude and experience.

 

[Joost R1200CL to R18TC]

LOL ... this is my first 'modern' engine! ... with my Shovelhead I wouldn't leave home with a set of spares (and a spare set of points!) and a wrench with me ... I am still getting used to this

Has anyone changed the lower set of plugs, the secondary ones? There appears to a single bolt holding the cover in place. However, once you have that out the cover still does not move. Any ideas or suggestions as to how to gain access?

 

[kate_brett]

Has anyone changed the lower set of plugs, the secondary ones? There appears to a single bolt holding the cover in place. However, once you have that out the cover still does not move. Any ideas or suggestions as to how to gain access?

Hopefully you get an answer before l get to 50,000 kms when l’ll change all 4 plugs.

 

[Keehn]

Has anyone changed the lower set of plugs, the secondary ones? There appears to a single bolt holding the cover in place. However, once you have that out the cover still does not move. Any ideas or suggestions as to how to gain access?

I took out the bottom plugs during my spring maintenance recently. The plastic cover (#5 in the microfiche below) just pulls out. The rear (closest to the engine body) of the plastic is a formed "C" that mates to a rubber grommet (#6 below). It simply pulls off and pushes back on, sort of like the side plastic covers that protect the ODBII port. Note in the microfiche that #6 has an angled groove that #5 fits into.

I don't particularly like this design tbh, because there's nothing but this single piece of plastic (and bolt) that secures the spark plug boot to the bottom plug. If it breaks, then there's no recourse but to buy another plastic "whatchamacallit" for $41.86 at current dealer prices.



Plus, I 100% disagree with the torque spec on these spark plugs (all four). When I pulled mine, the crush ring wasn't fully compressed. I retorqued to "gut-n-tight"...meaning until I knew all plugs were secure in their holes and ensure that zero blow-by occurs. In my 20+ years of "gut-n-tight", I've never once stripped a plug thread, so ymmv.

I also used some dielectric grease on the ceramic portions, as there was none present. Just peace of mind.

Mike

 

[Joost R1200CL to R18TC]

Thanks for description Mike. Helped a lot. Went through the process of changing the lower two spark plugs the weekend before last.

First, remove the bolt (#9) which will allow the plastic cover to drop down, revealing the sparkplug boot. The plastic cover just slides off from a rubber slot. There is a wiring bundle right at the base of the plastic cover. You can slide that off, just use a small flathead screwdriver to push the clip securing it aside and slide apart. Takes no force. No need to clip the plastic tie.

The next step is to unclip the sparkplug boot. You will have to press the light grey release button to unclip it. Again, like anything plastic, if you are using force... you are doing it wrong and you will break something. (An error I have committed many times so have become rather cautious before pulling on things). The light grey button releases easily and the sparkplug boot can just come off.

Next is to remove the sparkplug itself. You will need to remove the decorative valve covers and push the rubber protectors out out of the way. Also, a 10-15cm extension is required. Do order the BMW specific spark plug socket, it will save you a lot of headache.

After that, reverse the process. (clean everything up while you are down there, it maybe years before you are back in there and those spark plug boots tend to rust if not polished every once in a while) For the sparkplug: 12Nm., there is no indication for the bolt holding the plastic cover, but using standard tables I set it at 8Nm, which appears to hold just fine) Incidentally, be very cautious when putting that little bolt holding the cover back in. The plastic cover 'pushes' at it is press-fit into a rubber grommet on the other end. The pressure will misalign your bolt and strip the thread at the tip if you are not careful, after which it will refuse to go in. (Making me resort to my handy threat repair tool kit - not fun). Get it aligned just right and make sure it grips right from the first turn or 'abort, realign, retry'

The left side works just the same. Just, you will have to take the horn off first. Unbolt but no need to unclip, just move it aside.

Right side takes about 25 minutes, left side 40 minutes. (Adding time for the horn and the fact that this cylinder is a little lower. (I am sure the next time around will be a lot faster)

One observation.... I got the bike factory new... and the bolts holding the plastic cover are different than what BMW shows in the graphs or what my local dealer in Marbella is supplying. No idea why they would be there... As you can see in the first photo, the head of the bolt has a little riser.... no idea why. Would love to know if others have found the same odd bolts holding the covers up.