Spark plug option?

[markstertt]

I'm coming up on 8k miles and see that Yamaha wants us to change the sparkplugs, at first this sounded way conservative but after checking some posts, it appears these LMAR8A-9 plugs actually need replacing at this low mileage and those who didn't had suffered poor performance.
 
When plugs are difficult to access (modern cars/bikes), I look for what I hope will be the longest lasting option such as platinum or iridium. I just found the NGK LMAR8AI-8 iridiums on the internet and can't see why these wouldn't be a good alternative. The only difference other than fine wire iridium is the -8 designation which indicates a .8mm gap or .032" which shouldn't be a problem and easily changed if so desired.
 
 
Does anybody have any reason to think these plugs wouldn't be a good alternative (other than approx. 2x price)? Or is anyone already using them? Thanks, Mark 

[Guest Ralph]

Not had them on the 07 but had some iridium plugs in a Suzuki it used to eat plugs and
they cured it, cant say I noticed any difference in performance though it maybe started
a bit better, I will likely fit them when the time comes.

[jake]

Iridium is a good way to go in a car they should be good for 100,000 on a bike I have no clue. I change my plugs on the FZ with over 12,000 and they looked great IMO hardly any build up. I could have just cleaned them up and they probably would have been good for another 12.
I put back in OEM NKG's

[markstertt]

Thanks for replies, I wonder why some owners were reporting their plugs were worn out at the 8k mile range? I think I will buy the Iridiums because I'm lazy and don't like to pull the bike half apart just to change plugs and the iridiums should extend time between changes. It will be 3-4 weeks before I get around to it but will follow up if anything interesting is found...Mark

[markstertt]

Ok, so I had to order the iridiums from a German site on the internet, with shipping came to $14 per plug or about twice the std. plug. The center electrode is the fine wire iridium and what I didn't know is that the ground electrode has a small platinum pad welded to it so wear should be minimal over long mileages. This plug is used in BMW's 1600cc but the internet dealer wanted over $20 ea. from them, BMW, your dealer may be better.

[sorkyah]

 
 

I'm coming up on 8k miles and see that Yamaha wants us to change the sparkplugs, at first this sounded way conservative but after checking some posts, it appears these LMAR8A-9 plugs actually need replacing at this low mileage and those who didn't had suffered poor performance. 
When plugs are difficult to access (modern cars/bikes), I look for what I hope will be the longest lasting option such as platinum or iridium. I just found the NGK -8 iridiums on the internet and can't see why these wouldn't be a good alternative. The only difference other than fine wire iridium is the -8 designation which indicates a .8mm gap or .032" which shouldn't be a problem and easily changed if so desired.
 
 
Does anybody have any reason to think these plugs wouldn't be a good alternative (other than approx. 2x price)? Or is anyone already using them? Thanks, Mark 

 
If going to the iridium plugs, could you not also go to a slightly colder plug LMAR9AI or
LMAR10AI? The iridium would prevent buildup alot better than a standard copper alloy plug. Possibly making it a more effeceint burn?

[markstertt]

From what I understand, the iridium is still a copper core plug and I have no reason to think a colder plug would be an advantage in a stock engine with stock C.R. on the street, however with higher c.r. and in a race bike then maybe so. On the street the plug needs to be hot enough for low speed, around town, idling etc. and still cool enough to dissipate heat at higher h.p. output on the highway or semi race situations. In basic street riding, a colder plug may not be desirable, unless someone with a lot of experience says otherwise, I'd stick to factory recommended heat range. I chose to try the iridium more for long wear with consistent performance characteristics, perhaps easier starting and better economy if the advert is to be believed...Mark (besides, I can't leave well enough alone)

[gregjet]

On this bike I think a colder plug might be as hindrance. Th lower reving, longer burn time in the cyl is probably plenty of time to clean the plugs and ditch the heat.
Too cold a plug will soot up faster.
Many things manufactures make wrong ( usually as a result of the intervention of accountants and stylists)decisions on their products but spark plugs they usually get reasonably right. I agree a finewire electrode plug would be better though ( see accountants). A note of caution that MAY be out of date. For a number of years iridium plugs had he reputation of spontaneously snapping the centre electrode surround ceramic. Very frustrating to find as when it is in the bike the elkectrode is down and the insutalor covers the gap. When you take it out and turn it the other way up the insulator falls back into it proper place and looks fine. Had it happen on cars AND bikes. It could be fixed by now but I have no information to confirm nor deny that.
If you are racing/track work you might need to change the range especially if you have modded the bike.
One thing that could mean a different plug is needed is if the ecu is reflashed or an aftermerket injection controller is fitted. Then it is possible you MAY need a HOTTER plug as the std bike runs reasonably lean which INCREASES the temperature. That you would have to check

[warnock]

Dealer gave me LMAR7A-9 does anyone know if these would work?

[mjh937]

Dealer gave me LMAR7A-9 does anyone know if these would work?

After some Internet research it looks like the lower the number the hotter the plug. I doubt there would be a problem, but if it was my bike I would get the correct plugs. 

[chuckles]

Dealer gave me LMAR7A-9 does anyone know if these would work?

 
Get the correct plugs, 7 is 200° hotter than the stock 8.

[markstertt]

I thought I had updated the information here about the Iridiums I installed but apparently not, so must have been somewhere else. If you buy these plugs, LMAR8AI-8, know that the top cap of the plug doesn't unscrew, so they can't be used in our application unless you are able to modify them. I eventually chucked them up in the lathe and used a tool post grinder to reduce the top post to the diameter of the stock plugs post then used a small cut off wheel to simulate the grooves for proper coil over push on retention. Otherwise, they work as expected and yes I would go to the trouble again but it should be a long time from now.

[AlbatrossCafe]

Here were my stock plugs compared to new ones after 8k. They definitely needed changing. I don't ride particularly hard either - mostly just commuting. I put the same kind back in because all the fancier long-lasting ones were more than twice the price with everything all said and done. Didn't seem worth it.
 
 
http://i.imgur.com/pmpZVGD.jpg
 
http://i.imgur.com/KNwO3Vn.jpg

[chuckles]

Did anyone use a little plug anti-seize when they reinstalled? I used a very small amount about 8 threads up from the tip.

[markstertt]

Yes I did and probably always will even though another member pointed out that the NGK factory info says the plugs are plated with a product that negates the need for anti seize but 50 years of doing something one way, with no problems is hard to change...Mark

[robborboy]

Did anyone use a little plug anti-seize when they reinstalled? I used a very small amount about 8 threads up from the tip.

I've always used NGK(they come retreated with an antiseize coating). I ride 12 months a year, rain, snow, etc. Never had a plug seize once.
 

[markstertt]

Did anyone use a little plug anti-seize when they reinstalled? I used a very small amount about 8 threads up from the tip.

I've always used NGK(they come retreated with an antiseize coating). I ride 12 months a year, rain, snow, etc. Never had a plug seize once.

If you do nothing else, clean the plug threads with a wire brush before reinstalling, if reusing the old plugs. If your carefu, you can do this on your wire wheel but do not wire wheel  the electrodes or the porcelain insulator, I've been led to believe that the wire tracks left on the porcelain can cause tracking/misfiring. If you happen to drop or fling the spark plug across the shop, then consider the plug garbage as you may have unknowingly cracked the insulator where you can't see it which could change the heat disappating quality of the plug or perhaps cause physical failure of the plug which could lead to engine damage.  
Just to play devils advocate, being an aircraft mechanic for over 30 yrs., I've probably gapped, cleaned & tested well over 10,000 spark plugs (or more) and always used Champion spark plug anti-seize and also never seized a plug that I know of. I have, however, had stubborn removals from engines of outside aircraft with unknown history. I had a guy walk into the shop one day while I was brushing anti-seize on a tray of plugs and the first words out of his mouth were "I never use that stuff unless I have a problem" Hmmm? Didn't know him and didn't see a need to respond.
 

[chuckles]

Did anyone use a little plug anti-seize when they reinstalled? I used a very small amount about 8 threads up from the tip.

I've always used NGK(they come retreated with an antiseize coating). I ride 12 months a year, rain, snow, etc. Never had a plug seize once.

I used a very small amount just to cover my bases, I traditionally do not use it and have never had a problem on previous vehicles. The nickel plating on NGK plugs should protect it from galvanic corrosion but I figured better safe than sorry.

[junfeng1116]

where did you guys buy the plug from? any source?

[markstertt]

where did you guys buy the plug from? any source?

If you mean the iridium version that needs the top post modified, I believe I found them on ebay from a German company in a set of 4, stock should be available at Yamaha dealer or also on ebay or perhaps amazon. If you can't find a source for iridium version let me know and I'll back track but you must know they aren't plug and play and easy to damage if you're not careful while modifying. Oh, the iridium version are used in the BMW 1600cc 6 cyl. bike but are more expensive from Beemer dealer and will still need to be modified. 

[rhb]

From what I understand, the iridium is still a copper core plug and I have no reason to think a colder plug would be an advantage in a stock engine with stock C.R. on the street, however with higher c.r. and in a race bike then maybe so. On the street the plug needs to be hot enough for low speed, around town, idling etc. and still cool enough to dissipate heat at higher h.p. output on the highway or semi race situations. In basic street riding, a colder plug may not be desirable, unless someone with a lot of experience says otherwise, I'd stick to factory recommended heat range. I chose to try the iridium more for long wear with consistent performance characteristics, perhaps easier starting and better economy if the advert is to be believed...Mark (besides, I can't leave well enough alone)

All good reasons to choose Iridium, the myth that Iridium plugs increase performance is marketing hype, the best conductor is copper, they just don't last as long. Iridium plugs advantages are longevity , efficiency (better mileage), and consistency over time. In my carbureted bikes I always switched to Iridium after up jetting and tuning to preserve the tune longer. Otherwise I would need to fiddle with carb settings constantly.
With an ECU controlled bike there is really not much need for this except, longevity, 30- 40 thousand miles before change.
 
The old adage about cold plug for highway and hot plug for city use is outdated, modern ignition systems  don't require this, stick to the recommended heat range for your engine, especially with these long reach plugs. You don't want to be increasing cylinder head temps or messing with EGT settings. Also running a hotter plug than required raises the ignition temperature at the plug, but the Cylinder head temperature will be lower, something most people don't consider. It is all about balance, running the plug hot enough to self clean, but not hot enough to burn off electrodes, or cause preignition.
 
 Now the issue of finding the plugs with no terminal cap, or removable cap, turning down the tip in a lathe is not a viable option for me or most other people. Did anyone find a drop in replacement? I did a little internet searching in Vane, but online sources and conversion charts are often out of date.
 
BTW,  the heat range index is different for every manufacture, be careful when cross referencing, some go down some go up for hotter/colder plugs, and numbering systems are all a little different
 

 

[markstertt]

I would imagine sooner or later one of the other plug manufacturers will come out with a fine wire plug for us, I just couldn't find one when I wanted it and when I ordered the NGK iridiums I didn't know that the top cap didn't come off but where there's a will there's a way. Just to clarify, the top of the plug is a very hard alloy and I ruined a plug trying to turn it, couldn't support the plug well enough to do this (at least I couldn't) but could grind it to size easy enough.

[rhb]

I think we are stuck with standard plugs for now. I did some searching, using Denso NGK cross reference, there isn't even a standard Denso plug that matches the NGK LMAR8A-9, let alone an Iridium or platinum. If Denso doesn't have it probably no others will either. It was a good idea while it lasted.
Here is a pic of the specs of out NGK if anyone wants to try to cross reference manually, I don't need to do this for a while so I am going to wait until I need to replace plugs.

 

 
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