NGK spark plug options

[Jonnyteabag_imp]

Hi, firstly please forgive me if this has been posted before but here in the UK NGK only have one spark plug listed for our bikes - LMAR8A-9S, which we all know is just the standard type.
I see that upgrade "high performance" plugs have been found listed in Japan, but I found that the Honda Africa twin uses the NGK iridium version of our standard plug and has the all important stainless sealing washer.
Part number SILMAR8A-9S (90992)

These are super expensive here in the UK but they will be easier to find as the Africa Twin is very popular world wide.
Just another option for any high milers on here that hate changing plugs! LOL!

Ride safe folks,
JT

[Davidjill_imp]

Hi, firstly please forgive me if this has been posted before but here in the UK NGK only have one spark plug listed for our bikes - LMAR8A-9S, which we all know is just the standard type.
I see that upgrade "high performance" plugs have been found listed in Japan, but I found that the Honda Africa twin uses the NGK iridium version of our standard plug and has the all important stainless sealing washer.
Part number SILMAR8A-9S (90992)

These are super expensive here in the UK but they will be easier to find as the Africa Twin is very popular world wide.
Just another option for any high milers on here that hate changing plugs! LOL!

Ride safe folks,
JT

I thought that the s on LMAR8A-9S stood for Stainless washer these are about £13.50 in the UK from places like Demon Tweeks. Who incidently have SILMARA-9S on special offer with 52% off

https://www.demon-tweeks.com/ngk-iridium...lsrc=aw.ds

[JRD]

“I found that the Honda Africa twin uses the NGK iridium version of our standard plug . . . Part number SILMAR8A-9S (90992)“

This is not correct. The SILMAR8A-9S plug has a different terminal configuration.

The CB1100 plug terminal is thinner and ridged. The Africa Twin plug terminal is wider and smooth. It does not fit.

[Gone in 60]

Whatever ya do, don't buy NGKs from eBay or Amazon. I got a set of fakes on eBay for our CRV when it hit 100k. The car started bucking at 110k, and I found that the ground electrodes on two of the plugs had evaporated. Checked NGKs site, and they had a warning on how to spot fake plugs, and mine definitely were.

[JRD]

I contacted NGK customer service and asked if they have any high performance plugs that were compatible with the 2017 CB1100. They indicated that the NGK 91909 LMAR8BI-9 are compatible with the bike (https://www.sparkplugs.com/ngk-91909-lma...spark-plug)

I will order some and report back.

[Randy B]

“I found that the Honda Africa twin uses the NGK iridium version of our standard plug . . . Part number SILMAR8A-9S (90992)“

This is not correct. The SILMAR8A-9S plug has a different terminal configuration.

The CB1100 plug terminal is thinner and ridged. The Africa Twin plug terminal is wider and smooth. It does not fit.

You remove the screw on tip. Per NGK's own cross reference it is a direct cross.

[JRD]

Interesting. I didn’t realize that the plug terminal unscrewed and I wasn’t going to just start yanking on it with pliers to see what would happen. Sounds like we have a few options! That’s an unfamiliar feeling for a CB1100 owner.

[SportsterDoc]

The standard NGK stock number 6817 ($5.99 at O'Reillys 6 years ago, currently $10.49) is a nickel-copper electrode, rated for 30,000 miles.

The NGK stock number 91909 is an iridium electrode, rated for 100,000 miles. Probably not much performance difference, but a "lifetime" spark plug. Currently $17.99 at O'Reillys

Otherwise they are the same:
10mm threads
26.5 mm reach
9/16 (14mm) hex
heat range 8

Not seeing a difference between 90992 and 91909