Spark Plugs

[treytexag_imp]

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

It took a little over a week for a large Honda dealer in Houston to order and receive my replacement spark plugs. And Ferret spot on, I believe they were about 19 bucks a piece. Plus install costs . . . .

 

[Ole]

I pulled my plugs @ 5000 miles to inspect. No re gaping no cleaning they were fine. Anti seize on the threads and back in. I will pull again @ 12000 miles.

 

[Xyzzy_imp]

I pulled my plugs @ 5000 miles to inspect. No re gaping no cleaning they were fine. Anti seize on the threads and back in. I will pull again @ 12000 miles.

FWIW: http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

Quote:NGK spark plugs feature what is known as Trivalent plating. This silver or chrome colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. This coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers whom have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.

 

[the Ferret]

Wow, that's interesting

 

[CIP57_imp]

I change out quite a few plugs each year and never use anti seize, plus don't bother torquing the plug if you use it, you will not get a proper reading.

 

[mattmcuomo@yahoo.com]

What's the best way to get to the inner plugs? I've got the slim socket...

Sent from me......

 

[kennyw]

What's the best way to get to the inner plugs? I've got the slim socket...

Sent from me......

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.

 

[Randy B]

Use the factory socket.

 

[Toro5xi_imp]

Thanks for posting this. I thought I had all the spark plug sockets I needed. Glad Father's Day is coming.

 

[the Ferret]

Toro..do you have the one in post 1 of this thread? You can use a 13 mm box end wrench, 14 mm box end wrench or 1/4" drive ratchet I believe

 

[mattmcuomo@yahoo.com]

Did you remove the tank?

Sent from me......

 

[kennyw]

What's the best way to get to the inner plugs? I've got the slim socket...

Sent from me......

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.
Or was that 3/8 ratchet with 3/8 to 1/4 adapter? Now I may need to run down to the garage and double check.

 

[mattmcuomo@yahoo.com]

What's the best way to get to the inner plugs? I've got the slim socket...

Sent from me......

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.
Or was that 3/8 ratchet with 3/8 to 1/4 adapter? Now I may need to run down to the garage and double check.

1/2" drive ratchet and 1/2 to 3/8 adapter should put you below the frame and over the valve cover.
Or was that 3/8 ratchet with 3/8 to 1/4 adapter? Now I may need to run down to the garage and double check. Must be 3/8 to 1/4.... Yep, that's it. Done! Thanks.

Sent from me......

 

[Toro5xi_imp]

Toro..do you have the one in post 1 of this thread? You can use a 13 mm box end wrench, 14 mm box end wrench or 1/4" drive ratchet I believe

Thanks for the hint. I do have both metric wrenches and 1/4 drive ratchet but most of my spark plug sockets are fairly thick walled and may not fit too well. I was just glad for the heads up on this and will see if what I have will work before starting the job. I am not close to needing plugs but may pull one just to see how the color looks.

One trick that can work in a pinch is if you do not have the proper spark plug socket is to use a deep socket of the correct size to unscrew the spark plug then use a long magnet to pull it out. When threading it back in use a piece of fuel line or rubber hose to lower it down in the hole and get it started. The nice thing about using the rubber hose is that it will slip and prevent cross threading if the plug does not start threading correctly. Then just use the deep well socket and torque.

 

[ryanschillinger_imp]

The plugs are $10.25 on Amazon and the tool is $17.
I ordered the stuff so I have it ready at 8k but that's gonna be a while anyway. I'm still about 1k.

 

[the Ferret]

That is a great price for these plugs.

 

[ryanschillinger_imp]

That's why I figured I better order now. Who knows if they'll have them available when I need them.

 

[Shinchan_imp]

***EDIT*****
There is some question about whether these are correct or not. They have a different washer than the Honda-specific version. I would not order until it is determined if these will work

************

In case anyone is in the market, an Ebay seller with a lot of good feedback (not me) sells a 4-pack of these for just a shade under $26.00 including shipping:

http://www.ebay.com/itm/4-pc-4-x-NG...MAR8A-9-4313-LMAR8A9-Tune-Up-wj-/121676142595

Not sure if this is a special deal or this is the price that these plugs have finally settled into, but I'm going to go ahead and buy a set to keep in my "someday" parts bin...

 

[the Ferret]

Wow that's like $6.50 each and free shipping. I already have a set in stock but getting ready to use those, so I'm in for a set. Thanks for the tip Shinchan

 

[Shinchan_imp]

I know, it's getting down to the "normal" NGK plug prices...

I wonder if in 40 years these weirdo plugs will be rarer than hen's teeth.

Wow that's like $6.50 each and free shipping. I already have a set in stock but getting ready to use those, so I'm in for a set. Thanks for the tip Shinchan