Spark Plugs

[the Ferret]

The CB 1100 takes special one off spark plugs designed for this bike. made by NGK they carry the designation LMAR8A-9S Honda part number 31908-MGC-003 and takes QTY 4. The bodies on these plugs are extremely thin as are the threads which are also extremely long at 26.5 MM or just over an inch.

The plugs are expensive at $19.99 each and it's highly unlikely your dealer will stock any so they will probably need to be ordered. A standard spark plug wrench is not going to work well given the small confines of the area to work in. However Motion Pro makes a thin walled 14MM narrow plug wrench that uses a 1/4" ratchet, a 13 mm box end wrench or a 14 mm box end wrench socket or T handle to loosen and tighten. It also has a rubber ceramic gripper up inside. Your dealer can get this from one of his suppliers or you can order it directly from Motion Pro

This pic illustrates just how small these plugs and tool are, On the left is a standard spark plug socket next to the Motion Pro Unit.
On the right is a standard spark plug next to the plug used in the CB 1100. Gap .031-.035 using a wire type feeler gauge is recommended.

L to R std spark plug socket, thin walled 14 mm Motion Pro spark plug socket, std spark plug, LMAR8A-9S spark plug for CB 1100

[url=http://smg.photobucket.com/user/theferret111/media/image.jpg1_zpsakibhpti.jpg.html]

[SanPete_imp]

Thank you ferret for this excellent write up.
How many miles can we expect from the original spark plugs before replacing?

[redbirds_imp]

Thanks for the post Ferret, good pics and comparison. Have you done a plug or valve inspection on your DLX?

[Novice_imp]

Does motion pro only sell only one 14 mm wrench? I think I found it on their website, but with no part number and our model not listed, I want to be sure I'm ordering the correct one. Where did you order your plugs from?

[redbirds_imp]

Here it is.

http://www.motionpro.com/motorcycle/partno/08-0512/

[the Ferret]

Thanks for the post Ferret, good pics and comparison. Have you done a plug or valve inspection on your DLX?

Neither. Turned over 13,000 miles on todays ride.

Does motion pro only sell only one 14 mm wrench? I think I found it on their website, but with no part number and our model not listed, I want to be sure I'm ordering the correct one. Where did you order your plugs from?

Go by description. I don't know how many they make. my box has a bunch of numbers on it
157174
08-0512
194989

Here's the tool as googled from Motion Pro

http://www.motionpro.com/motorcycle/partno/08-0512/

I know I took in the Motion Pro part number in the link above 08-0512 with me and the parts person had to look it up by description from her supplier (not Motion Pro)

I got plugs and tool from local dealer. Tool was $19.99

[Novice_imp]

!!!

[furious_blue_imp]

yes, thanks for the tip !

there's nothing like setting time aside for a chore only to find that you're hopelessly ill-equipped to carry out the task...

This probably saved me a bit of time and frustration !

[ish_imp]

Thank you!!!! Saving me a headache.

[the Ferret]

I might mention that a dab of "never-seize" on those plug threads would be a great idea when you replace them

Thank you ferret for this excellent write up.
How many miles can we expect from the original spark plugs before replacing?

San Pete, I don't know we are in uncharted waters on this. I know the Aussies have put enough KMs on their bikes and I believe have had plugs replaced but it is apparently part of their service over there. Not sure if theirs were replaced "just because" or if they actually needed them with wear and tear evident?

Honda calls for an inspection at 8,000 miles. Not sure when they recommend replacement, I will have to look that up.