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This procedure is for a stock bike with no modifications.
For bikes with any mods that would effect the procedure, adjust accordingly
Tools required:
Stock spark plug socket (or equivalent 18mm socket)
8mm socket (or wrench)
17mm socket
Ratchet
Ratchet extension
Pliers
Wire cutters
Spray can of some type of petroleum distillate cleaner
Piece of sandpaper
Spark plug gap gauge
Flat head screwdriver
Rags
Remove the seat, gas tank, and main fairing.
See Seat, tank, fairing removal tutorial.
![]()
Disconnect pair valve and move to the side.
![]()
Remove the reed valve covers, each cover has two 8mm bolts to remove.
Pull the spark plug caps off the spark plugs.
![]()
Use compressed air or a vacuum to clean out the spark plug area.
This keeps debris from getting in the cylinder.
![]()
Unscrew this cap on the coil.
Try using your fingers to do this, but if it is too tight you can use a pair of pliers to carefully loosen it first. Once the cap is off you can pull the wire out.
The spark plug cap comes off the wire by simply unscrewing it.
![]()
When you look inside the part of the cap that goes on the spark plug, you will see a couple of grooves that a flathead screwdriver will fit in. Take a flathead screwdriver and unscrew this.
![]()
Exploded view of the cap and wire.
![]()
On the part of the wire that goes to the coil, there is a rubber grommet ~33mm from the end of the wire, a plastic O-ring with a beveled edge, and the cap that holds it on. All of these are one way direction specific upon reinstallation.
Clean all the parts of the cap inside and out using a spray cleaner and a rag. (I'm using "STP Wire Dryer") Compress air could also come in handy to help aid in this (but not necessary).
![]()
You can use a small piece of rolled up sandpaper to help clean this guy out.
Check the condition of the wire.
If there are any cracks in the insulation, the wire will need to be replaced.
If the insulation is good, you can renew the ends of the wire by taking wire cutters and clipping ~1/4 inch off the ends. This will remove corrosion off the ends of the wire and take it to fresh wire.
![]()
Before picture of wire end with corrosion.
![]()
After picture of the same wire after cutting the end off.
Although I have just been replacing the wires with new ones every couple of years, using 7mm spark plug wire.
Once the cap is clean and the wire looks good you can go ahead and put it back together and replace on the coil.
Side note:
It is best to only do one cap at a time, that way if you run into a problem remembering how it assembles, you still have the other one to use as a reference.
Remove the plugs. If you don't have the factory spark plug socket, you will need a thin walled 18mm socket to do this.
![]()
This is the factory spark plug socket with a 17mm socket, an extension and ratchet.
![]()
Using a long extension makes it easy to clear everything.
![]()
Check the gap on the new plugs.
They come pre gapped but should be checked anyway to be sure. The gap should be 6mm-7mm (.024-.028 inches)
Install the new plugs.
Do not over tighten them, the torque value on them is 10ft.lbs. So just snug.
That's the end of the procedure, assembly of everything else is the reverse of the disassembly. The bolts on the pair valve cover also just barely need to be snug.
For bikes with any mods that would effect the procedure, adjust accordingly
Tools required:
Stock spark plug socket (or equivalent 18mm socket)
8mm socket (or wrench)
17mm socket
Ratchet
Ratchet extension
Pliers
Wire cutters
Spray can of some type of petroleum distillate cleaner
Piece of sandpaper
Spark plug gap gauge
Flat head screwdriver
Rags
Remove the seat, gas tank, and main fairing.
See Seat, tank, fairing removal tutorial.
Disconnect pair valve and move to the side.
Remove the reed valve covers, each cover has two 8mm bolts to remove.
Pull the spark plug caps off the spark plugs.
Use compressed air or a vacuum to clean out the spark plug area.
This keeps debris from getting in the cylinder.
Unscrew this cap on the coil.
Try using your fingers to do this, but if it is too tight you can use a pair of pliers to carefully loosen it first. Once the cap is off you can pull the wire out.
The spark plug cap comes off the wire by simply unscrewing it.
When you look inside the part of the cap that goes on the spark plug, you will see a couple of grooves that a flathead screwdriver will fit in. Take a flathead screwdriver and unscrew this.
Exploded view of the cap and wire.
On the part of the wire that goes to the coil, there is a rubber grommet ~33mm from the end of the wire, a plastic O-ring with a beveled edge, and the cap that holds it on. All of these are one way direction specific upon reinstallation.
Clean all the parts of the cap inside and out using a spray cleaner and a rag. (I'm using "STP Wire Dryer") Compress air could also come in handy to help aid in this (but not necessary).
You can use a small piece of rolled up sandpaper to help clean this guy out.
Check the condition of the wire.
If there are any cracks in the insulation, the wire will need to be replaced.
If the insulation is good, you can renew the ends of the wire by taking wire cutters and clipping ~1/4 inch off the ends. This will remove corrosion off the ends of the wire and take it to fresh wire.
Before picture of wire end with corrosion.
After picture of the same wire after cutting the end off.
Although I have just been replacing the wires with new ones every couple of years, using 7mm spark plug wire.
Once the cap is clean and the wire looks good you can go ahead and put it back together and replace on the coil.
Side note:
It is best to only do one cap at a time, that way if you run into a problem remembering how it assembles, you still have the other one to use as a reference.
Remove the plugs. If you don't have the factory spark plug socket, you will need a thin walled 18mm socket to do this.
This is the factory spark plug socket with a 17mm socket, an extension and ratchet.
Using a long extension makes it easy to clear everything.
Check the gap on the new plugs.
They come pre gapped but should be checked anyway to be sure. The gap should be 6mm-7mm (.024-.028 inches)
Install the new plugs.
Do not over tighten them, the torque value on them is 10ft.lbs. So just snug.
That's the end of the procedure, assembly of everything else is the reverse of the disassembly. The bolts on the pair valve cover also just barely need to be snug.
