the Ferret
Road warrior
gcarper? Holy cow early forum members are coming out of the woodwork this month?
How are you doing sir?
How are you doing sir?
Changing spark plugs
- Thread starter 3rdbike_imp
- Start date
Wisedrum
Road warrior
Changed plugs and airfilter at 32.000km for the first time because I thought it was about time to do so. The CB showed no symptoms to need a change though. Now after 66.000km I have to no intention to do another change. Just recently I finished a 6.500km trip around the Balticum. The CB didn't give the slightest hint or reason to worry. It just ran fine all the time, was always easy to start, had a very low fuel consumption with averagely 4,3l/100km and never had a hiccup. I leave plugs and airfilter inside.
I will order a set of plugs in this online shop whenever the next change will be, don't know yet.
Zuendkerze
Otherwise plugs for the CB are way too expensive and totally overpriced.
The CB is such a fine machine as elsewhere often been mentioned in this forum. It don't need much maintenance. Just a bit like an oil change every now and then as you like it. Maybe not even this.
Wisedrum
I will order a set of plugs in this online shop whenever the next change will be, don't know yet.
Zuendkerze
Otherwise plugs for the CB are way too expensive and totally overpriced.
The CB is such a fine machine as elsewhere often been mentioned in this forum. It don't need much maintenance. Just a bit like an oil change every now and then as you like it. Maybe not even this.
Wisedrum
misterprofessionality
Road warrior
for those of you that have done this, i have a dumb question. Does the gas tank have to be removed to complete this work?
the Ferret
Road warrior
Nope. Not if you have the right spark plug socket
redbirds_imp
Road warrior
I'm still on the original plugs and bike starts and runs great at 20,000 miles.
PowerDubs_imp
Road warrior
Modern engines- both on plug material and tuning- can run plugs a LOOOOOONG time.
My only concern would be seizing.
My brother in law asked my several years ago to assist in what apparently was the first tune-up of my sisters Toyota...at about 130k.
We went to loosen the first plug...no bueno. I asked him how does it run? He said fine. I said better not to strip the threads out of the cyl head on a car worth maybe 3-4k at that time.
She went on to drive the car for many tens of thousands of miles with zero issue.
My only concern would be seizing.
My brother in law asked my several years ago to assist in what apparently was the first tune-up of my sisters Toyota...at about 130k.
We went to loosen the first plug...no bueno. I asked him how does it run? He said fine. I said better not to strip the threads out of the cyl head on a car worth maybe 3-4k at that time.
She went on to drive the car for many tens of thousands of miles with zero issue.
misterprofessionality
Road warrior
Yep! i do. i bought the one you yourself suggested.The ferret_imp said:
peterbaron
Road warrior
I think deep M14?? does the job
Wisedrum
Road warrior
It will do. Django send me his special 14mm nut as a present. Thank you again, Django, because he sold his CB and never used it.
Don't think, that you can change all plugs without removing the tank. The outer ones will be fine, but you will get certainly into trouble with the inner ones. As I wrote, I changed the plugs once, but not with an installed tank. Good luck for all, who leave the tank on.
I though have no intention to change them again. As I understood, the same plugs are be used in the Honda Jazz and are good for a lot of miles. So they will also last a very long time in the CB, if you don't ride her
like racing bike.
Wisedrum
Don't think, that you can change all plugs without removing the tank. The outer ones will be fine, but you will get certainly into trouble with the inner ones. As I wrote, I changed the plugs once, but not with an installed tank. Good luck for all, who leave the tank on.
I though have no intention to change them again. As I understood, the same plugs are be used in the Honda Jazz and are good for a lot of miles. So they will also last a very long time in the CB, if you don't ride her
like racing bike.
Wisedrum
the Ferret
Road warrior
I didn't remove or even move my fuel tank when changing plugs. Here's how I did it (from my original pictoral on How To Change Spark Plugs).
Tools needed:
Air hose with spray nozzle
Stock Honda spark plug wrench or Motion Pro equivalent (what we are using here)
14 mm box end wrench
Spark plug gapping tool
4 Honda Spark plugs LMAR8A-9S Honda Part Number 31908-MGC-003
Start by putting the bike on the center stand. We started on the left side of the bike but that really is unimportant.
First thing you need to do is check the gap on the new plugs. Spec calls for .031-.035. Mine all came out of the box from the factory at .033. We re-gapped them to .031 to allow for wear down the road.
Take an air nozzle and spray the outside plug cavity to remove any debris. We don’t want any of that falling into the spark plug hole once the plug is removed.
Take off the outside spark plug cap and slide spark plug tool over the plug. Remove using 14 mm box end wrench. We also used a swivel head long handled ¼” drive ratchet since we had one available, but ended up using both tools as was necessary.
Inspect removed plug. As you can see mine was still in good shape, had a nice tan color on the ceramic, but gap had opened up to .037 (as electrode and ceramic wore over time). These could have been wire brushed clean, gap reset to factory spec and reinstalled. However as per my practice after 25,000 miles I went with new plugs.
With outside plug removed we had good access to the inside plug. Be sure and stuff some wadded up paper towel into the outside spark plug hole so nothing gets down in that cylinder, and again use spray nozzle to blow out any debris from spark plug cavities. Remove spark plug cap from inside plug.
A note here, if you have large hands there is not a lot of room to work on the inside plug.
Use your spark plug wrench and 14mm box wrench to loosen and remove inside plug. The Motion Pro tool has a rubber gripper inside which makes plug removal and installation easier than the factory spark plug tool.
Install the rear spark plug. Torque spec is 12 ft lbs on a spark plug. We couldn’t figure any way to get a measurement on this given the small confines of the space to work in. So we ran the plugs in until they touched then gave them a bit more, snugging them up. You certainly don’t want to over tighten them and risk stripping the threads of the spark plug hole.
Reinstall rear spark plug cap.
Remove the paper towel from the outside spark plug hole, and install a plug there. Install the spark plug cap.
Move to the other side of the bike and repeat the process for that side’s two plugs
Tools needed:
Air hose with spray nozzle
Stock Honda spark plug wrench or Motion Pro equivalent (what we are using here)
14 mm box end wrench
Spark plug gapping tool
4 Honda Spark plugs LMAR8A-9S Honda Part Number 31908-MGC-003
Start by putting the bike on the center stand. We started on the left side of the bike but that really is unimportant.
First thing you need to do is check the gap on the new plugs. Spec calls for .031-.035. Mine all came out of the box from the factory at .033. We re-gapped them to .031 to allow for wear down the road.
Take an air nozzle and spray the outside plug cavity to remove any debris. We don’t want any of that falling into the spark plug hole once the plug is removed.
Take off the outside spark plug cap and slide spark plug tool over the plug. Remove using 14 mm box end wrench. We also used a swivel head long handled ¼” drive ratchet since we had one available, but ended up using both tools as was necessary.
Inspect removed plug. As you can see mine was still in good shape, had a nice tan color on the ceramic, but gap had opened up to .037 (as electrode and ceramic wore over time). These could have been wire brushed clean, gap reset to factory spec and reinstalled. However as per my practice after 25,000 miles I went with new plugs.
With outside plug removed we had good access to the inside plug. Be sure and stuff some wadded up paper towel into the outside spark plug hole so nothing gets down in that cylinder, and again use spray nozzle to blow out any debris from spark plug cavities. Remove spark plug cap from inside plug.
A note here, if you have large hands there is not a lot of room to work on the inside plug.
Use your spark plug wrench and 14mm box wrench to loosen and remove inside plug. The Motion Pro tool has a rubber gripper inside which makes plug removal and installation easier than the factory spark plug tool.
Install the rear spark plug. Torque spec is 12 ft lbs on a spark plug. We couldn’t figure any way to get a measurement on this given the small confines of the space to work in. So we ran the plugs in until they touched then gave them a bit more, snugging them up. You certainly don’t want to over tighten them and risk stripping the threads of the spark plug hole.
Reinstall rear spark plug cap.
Remove the paper towel from the outside spark plug hole, and install a plug there. Install the spark plug cap.
Move to the other side of the bike and repeat the process for that side’s two plugs
max
Road warrior
In addition to Ferret's comprehensive description i would like to add some pictures to illustrate, i have just removed the inside plug and found;
small rocks inside the sparkplug well just to the right of the spark plug;
The ratchet does work in the confined space, one click at a time but do the rest by hand;
And easier with a "wobble extension";
and the extension;
So there is a risk of debris ending up inside the cylinder, unless you can prevent this it may be time to postpone until the area around the plugs can be cleared out completely, i used an empty weed sprayer which had enough of a blast of air to clear all debris out and the reach to get in behind the spark plugs.
small rocks inside the sparkplug well just to the right of the spark plug;
The ratchet does work in the confined space, one click at a time but do the rest by hand;
And easier with a "wobble extension";
and the extension;
So there is a risk of debris ending up inside the cylinder, unless you can prevent this it may be time to postpone until the area around the plugs can be cleared out completely, i used an empty weed sprayer which had enough of a blast of air to clear all debris out and the reach to get in behind the spark plugs.
Houtman_imp
Road warrior
Changing the spark plugs on a CB 1100 is not as difficult as changing a light bulb , only one person is needed for the spark plugs.
misterprofessionality
Road warrior
Thanks for all the tips about debris Ferret. I knew how dangerous that was but I didn't know how badly it can get stuck in there. Thankfully, my CB is not nearly as dirty as yours 
misterprofessionality
Road warrior
ok! for science, and for reference, for anybody that's asking "how often do i really need to change these?"
here's what they look like after 34000 miles of neglect
this was enough wear and tear to cause a very slight but noticable hesitation in the bike when maintaining a very small throttle opening at speed. about 55mph in 6th gear was the sweet spot to generate that hesitation. it didn't do it all the time, and the first time i think i ever noticed it was at around 33000 miles. it's also worth mentioning that upon measuring i found the gap to be way off. almost .4
Having swapped them out though the bike is back to 100%, and I can feel the power gain (or more accurately, i can feel the power i lost back in my hands). I figure i probably shoulda changed these at around 16k to keep everything in tip top shape.
here's what they look like after 34000 miles of neglect
this was enough wear and tear to cause a very slight but noticable hesitation in the bike when maintaining a very small throttle opening at speed. about 55mph in 6th gear was the sweet spot to generate that hesitation. it didn't do it all the time, and the first time i think i ever noticed it was at around 33000 miles. it's also worth mentioning that upon measuring i found the gap to be way off. almost .4
Having swapped them out though the bike is back to 100%, and I can feel the power gain (or more accurately, i can feel the power i lost back in my hands). I figure i probably shoulda changed these at around 16k to keep everything in tip top shape.
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