2020 R1250 GSA _ Spark Plugs

Does anyone know if I can substitute the plug used in the R1200 NGK LMAR80-J, for the one in the R1250 NGK LZMAR8AI-10 ? The latter is supposed to last twice as long 100,000 kms as the plug for the R1200 50,000 kms, but I have seen enough wear, in the 1250 plugs, to require re-gaping after as little as 20,000 kms. And they cost twice as much.

Is the R1200 plug numbered LMAR8D-J as in "8D" and not "80"? I can't answer your question but just want to make sure we're talking the right plug.

From NGK.com:

LZMAR8AI-10

Thread Diameter: 10mm
Thread Pitch: 1.0mm
Seat Type! Gasket
Reach: 26.5mm (1.04")
Hex Size: 9/16" (14mm)
Terminal Type: Solid
Gap: .039" (1.0mm)
Center Electrode Material: Iridium
Type: Fine Wire
Size: 0.6mm
Projection: Extended Projection
Ground Electrode Material: Platinum
Type: Standard
Quantity: 1

Specifications
Resistor: Yes
Resistor Value: 5k Ohm
Heat Range: 8

Torque Specs
Cast Iron: 7.2-10.8 lb. ft. Aluminum: 7.2-8.7 lb. ft.

Part Information
Brand: NGK/NTK
Warranty: 60 Days
Longevity: 100k Miles
———————————

LMAR8D-J

Thread Diameter: 10mm
Thread Pitch: 1.0mm
Seat Type: Gasket
Reach: 26.5mm (1.04")
Hex Size: 9/16" (14mm)
Terminal Type: Solid
Overall Height

Gap: .031" (0.8mm)
Center Electrode Material: Nickel
Type: Standard
Size: 2.5mm
Projection: Projected
Ground Electrode Material: Nickel
Type: Multi-Ground
Quantity: 2

Specifications
Resistor: Yes
Resistor Value: 5k Ohm
Heat Range: 8
Torque Specs: Cast Iron: 7.2-10.8 lb. ft. Aluminum: 7.2-8.7 lb. ft.

Part Information
Brand: NGK/NTK
Warranty: 60 Days
Longevity: 50k Miles

The two plugs are priced within $1.00 of each other from NGK.com. Same reach, thread, heat range, etc. but they list the OEM 1250 plug as “Extended Projection”, fwiw. The 1200 plug is multi-electrode and the two plugs carry different gapping from the mfg.

Best,
DeVern

GTRider said:

Same reach, thread, heat range, etc. but they list the OEM plug as “Extended Projection”,

Click to expand...

I thought both those plugs were OEM?
Do you mean OEM for the 1250?

There is some interesting reading by Wes Fleming in the latest owners news on this subject of using alternate plugs.

Lee said:

I thought both those plugs were OEM?
Do you mean OEM for the 1250?

Click to expand...

Yes, sorry-I’ll clarify that.

Best
DeVern

GTRider said:

From NGK.com:

LZMAR8AI-10

Thread Diameter: 10mm
Thread Pitch: 1.0mm
Seat Type! Gasket
Reach: 26.5mm (1.04")
Hex Size: 9/16" (14mm)
Terminal Type: Solid
Gap: .039" (1.0mm)
Center Electrode Material: Iridium
Type: Fine Wire
Size: 0.6mm
Projection: Extended Projection
Ground Electrode Material: Platinum
Type: Standard
Quantity: 1

Specifications
Resistor: Yes
Resistor Value: 5k Ohm
Heat Range: 8

Torque Specs
Cast Iron: 7.2-10.8 lb. ft. Aluminum: 7.2-8.7 lb. ft.

Part Information
Brand: NGK/NTK
Warranty: 60 Days
Longevity: 100k Miles

Best,
DeVern

Click to expand...

Thank you for the info! Installing new LMAR8AI-10 spark plugs today. 2019 R1250RT 12K mile service.

The plug specified for the R1250s is the NGK LMAR8AI-10, not NGK LZMAR8AI-10. I have no clue what the "Z" following the "L" means. Beemerboneyard.com now sells the NGK LMAR8AI-10 for $36.95 a pair. Unless someone can tell me what the Z designation means, I'll stick with the LMAR8AI-10.

"Z" with NGK means "extended gap". This may indicate the 0.039" gap instead of the 0.031", but I'm not sure...
The required gap typically depends on the ignition system of the engine, so select whichever BMW recommends.

From Tech Support at NGK.com:

“Hello,

The letter "Z" stands for Extended Projection which is refering to the center electrode:”
”

Best,
DeVern