LMAR8AI-10

[Rougarou]

Do I have to use this plug or is there a substitute?  I'm not gonna pay $26 per plug, need a cross referenced one. 

 

Its not even listed on the NGK website

 

 

Oh, and per the manual, I'm 8k past due to change these,.......what engines require changing every 12k for spark plugs???

[TEWKS]

@Boxflyer might know of an alternative. 

[roadscholar]

https://www.beemerboneyard.com/ngklmar8ai10.html

 

https://www.summitracing.com/search/part-type/spark-plugs?fr=part-type&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=LMAR8AI-8

 

 

NGK website...

This allows centre electrode diameters to reduce from 2.5mm using Nickel, to 0.6mm using Iridium or Platinum. The finer point means that once a spark forms, the flame kernel does not have a large mass of centre electrode that reduces absorption of heat and the flame shadow impeding the flame progress. This equates to a more complete burn that translates to:
 

• Improved acceleration
• Improved fuel consumption
• Smoother idling

NGK’s range of precious metal spark plugs provide two major benefits over conventional spark plugs:
 

• High Ignitability – is only achieved by utilising an exposed fine tip centre electrode allowing for superior flame growth.
• Long Service Life – is achieved by utilising a high percentage of precious metals patented by NGK.

 

Be glad there aren’t 6 or 12 of them, in the 70’s Bosch Platinum tip plugs for a 911S street car were about $8. each, they needed them, anything else would foul below 4000 rpm. The race engines used smaller diameter twin plugs that were $25-30. (X 12)

[Rougarou]

Summit doesn't have the LMAR8AI-10.  Beemerboneyard equates to $23 per shock with shipping.  It's a 1.2 liter engine, not high performance, standard performance and the plugs should not have to be replaced every 12k.

 

When I search the NGK website I find nothing on the LMAR8AI-10

 

If I don't find a better source/cross-reference, I'ma run 'em til I notice something funky going on,,.......and ya, I'm whining about $52 at the highest.

[TEWKS]

13 minutes ago, Rougarou said:

I'm whining about $52 at the highest.

x 2 I believe. I think that motor has 4 plugs. 

[Rougarou]

4 minutes ago, TEWKS said:

x 2 I believe. I think that motor has 4 plugs. 

 

two plugs brah,.....only two.

[TEWKS]

Yup, I just went there and realized I gave bad info. 

[roadscholar]

I was gonna say something smartass like maybe you shoulda got a Honda but then looked up plugs for an Africa Twin, it uses a similar plug except there are 4 of them : )

[Bernie]

2 hours ago, Rougarou said:

Summit doesn't have the LMAR8AI-10.  Beemerboneyard equates to $23 per shock with shipping.  It's a 1.2 liter engine, not high performance, standard performance and the plugs should not have to be replaced every 12k.

 

When I search the NGK website I find nothing on the LMAR8AI-10

 

If I don't find a better source/cross-reference, I'ma run 'em til I notice something funky going on,,.......and ya, I'm whining about $52 at the highest.

 

Must be GS problem, on the RT's we only change them every 12,000 miles.

[Rougarou]

2 hours ago, Bernie said:

 

Must be GS problem, on the RT's we only change them every 12,000 miles.

 

'zactly, that's much too often for a spark plug.  The GS calls for the same mileage, I'm 8k past due, bikes firing fine, not idle differences, no mileage drops......nothing different from the day I first rode it 20k ago.

[Dave_in_TX]

Try sparkplugs.com.

[Bernie]

I think Amazon also has these plugs for RT’s.

This post should be really in the WetHead or ShiftCam section. Just saying.

[Rougarou]

5 hours ago, Bernie said:

I think Amazon also has these plugs for RT’s.

This post should be really in the WetHead or ShiftCam section. Just saying.

 

Not that I can find plenty of -8's and -9's but zero -10's

[BrianM]

The number after the dash is the gap in tenths of a mm. 8 = .08 mm, 10 = 1.0 mm.

 

According to NGK the plugs can be regapped - https://www.ngk.com/proper-ngk-gapping-instructions.

When setting the gap on a fine wire center electrode, you cannot touch the center electrode or the porcelain (on any plug), only the side electrode. Need a real gapping tool. Biggest danger would be damaging the cnter electrode and the iridium tip falling off.

The limit is a change of .008 in = .2 mm. 

 

So in theory a -9 (even a -8) could be gapped to a -10.

I have never gapped one of these plugs, so the risk is yours.

 

Also beware of fake plugs on Amazon and Ebay.

[Rougarou]

16 hours ago, BrianM said:

The number after the dash is the gap in tenths of a mm. 8 = .08 mm, 10 = 1.0 mm.

 

According to NGK the plugs can be regapped - https://www.ngk.com/proper-ngk-gapping-instructions.

When setting the gap on a fine wire center electrode, you cannot touch the center electrode or the porcelain (on any plug), only the side electrode. Need a real gapping tool. Biggest danger would be damaging the cnter electrode and the iridium tip falling off.

The limit is a change of .008 in = .2 mm. 

 

So in theory a -9 (even a -8) could be gapped to a -10.

I have never gapped one of these plugs, so the risk is yours.

 

Also beware of fake plugs on Amazon and Ebay.

 

Ya, I knew what the digits all mean.....but since the manual calls specifically for that part number, I erroneously thought it would be available to the masses as mass produced products should be.

 

 

So, I may just by some of the 8's and do this:

 

[BrianM]

1 hour ago, Rougarou said:

 

Ya, I knew what the digits all mean.....but since the manual calls specifically for that part number, I erroneously thought it would be available to the masses as mass produced products should be.

 

 

So, I may just by some of the 8's and do this:

 

Since you are opening the gap, would be better to get a tool like this than use a pliers. 

 

I have used one for many years.

 

Maybe no other company specs that plug with a -10 gap, so not very common.

 

Went through about a dozen $25 plugs and 4 $70 plug caps in a race season

[Dave_in_TX]

On 8/13/2021 at 11:00 AM, Rougarou said:

 

'zactly, that's much too often for a spark plug.  The GS calls for the same mileage, I'm 8k past due, bikes firing fine, not idle differences, no mileage drops......nothing different from the day I first rode it 20k ago.

At 12000 miles the plugs in my 2020 R1250GS looked fine so I put them back in. At 24000 miles they looked like this:

Although I did not notice any change in idle, performance or fuel economy, If you look close, you will see that the tips are burned off. I found a thread on a different forum where the original poster had th same problem. The poster claimed to have been in contact with NGK who informed him that the stock plugs were too hot. He switched to LMAR9AI-10. That's what I'm currently running. They've only bee in for a bit over 12k miles so I don't yet know if they will last longer. However, the bike runs fine with the colder plug which is available at sparkplugs.com for $12.17.

[Rougarou]

1 hour ago, Dave_in_TX said:

At 12000 miles the plugs in my 2020 R1250GS looked fine so I put them back in. At 24000 miles they looked like this:

Although I did not notice any change in idle, performance or fuel economy, If you look close, you will see that the tips are burned off. I found a thread on a different forum where the original poster had th same problem. The poster claimed to have been in contact with NGK who informed him that the stock plugs were too hot. He switched to LMAR9AI-10. That's what I'm currently running. They've only bee in for a bit over 12k miles so I don't yet know if they will last longer. However, the bike runs fine with the colder plug which is available at sparkplugs.com for $12.17.

 

Thanks, just ordered

[WBinDE]

I wonder why BMW specs the LMAR8AI-10 if it runs so hot that NGK recommends that @DaveInTx use the cooler LMAR9AI-10? Yes, Texas in the summer is hot, and perhaps he runs the bike hard, but shouldn't the cooling system mitigate those factors?

[Dave_in_TX]

11 hours ago, WBinDE said:

I wonder why BMW specs the LMAR8AI-10 if it runs so hot that NGK recommends that @DaveInTx use the cooler LMAR9AI-10? Yes, Texas in the summer is hot, and perhaps he runs the bike hard, but shouldn't the cooling system mitigate those factors?

I'm not the one to whom NGK recommend using a cooler plug. That was a poster on a different forum with same problem. I do not usually run my bike hard and the 24k I had on my plugs included Texas winter.

 

The cooling system will do little to mitigate a plug with too hot of a heat range.

[WBinDE]

@DaveInTx Reading comprehension fail, sorry. Still wondering why BMW recommends a different plug than NGK, though - I'd think they'd be on the same page.

[Rougarou]

1 hour ago, WBinDE said:

@DaveInTx Reading comprehension fail, sorry. Still wondering why BMW recommends a different plug than NGK, though - I'd think they'd be on the same page.

 

A tale of two engineers,........that's why.

[Dave_in_TX]

20 hours ago, WBinDE said:

@DaveInTx Reading comprehension fail, sorry. Still wondering why BMW recommends a different plug than NGK, though - I'd think they'd be on the same page.

Different perspectives.

NGK responded to an issue of the plugs tips burning off which they assumed was due o the plug running too hot. NGK did not specifically say that the proper plug was the LMAR9AI-10.

 

I think BMW switched to iridium plugs for emission control rather than for longer plug life. The previous three iterations of the 1200 have used a plug with a numbered heat range of 8 and specified a 12k mile replacement interval. the iridium alternate plug for the 1200 LC standard is the LMAR8AI which is probably why BMW went with it. BMW may not have encountered the issue of the tips burning off although there are reports on multiple forums orts off this happening.

 

Interestingly, the NGK support people are not in complete agreement regarding the most appropriate iridium plug for the 1200 LC. A poster on one forum was told by the NK tech that  the LMAE8AI-8 was appropriate while a poster on a different forum was recommended the LMAR9AI-8. The reason the second one recommended the LMAR9AI-8 was because the LMARxAI-x plugs are slightly longer than the OEM 1299 LC plugs so that NGK tech thought the plug might run hotter due to being slightly further down in the combustion chamber.