If your bike has vibrations in the seat, handle bars or foot pegs, read on as this procedure "may" help reduce some of those harmonic vibrations. If you can remove the spark plug caps, you can check this and correct this condition.
WHAT IS THE CAUSE?:
The the Spark Plug Cap (SPC) threads into the High Tension Lead (HTL) wire core using a brass screw with a conventional clockwise thread. As the wire ages, the insulation around the wires core may relax allowing the copper core wire to move away from the caps brass screw. This loss of connection translates to vibrations across throughout mid to upper RPM's. Remember this is a waste spark ignition and each coil is responsible for 2 spark plugs firing and a poor connection at either plug can alter the timing, energy, or duration of the spark to a cylinder! We feel this as harmonic vibration in the bars and seat. The good news is, its easy to fix!
IMO - unless the wires core is completely broken, it IS NOT responsible for a misfire! That is, the engine will start, idle, and accelerate fine. But the chassis may have harmonic vibration from about 4K on up.
HOW TO CHECK IT AND CORRECT IT:
*** ADDITIONAL TESTING; If you have a DMM (Digital multimeter) and want to test the resistor internal to the SPC, see section below for additional testing before installing the cap onto the wire.
SPC INSTALLATION INTO VALVE COVER:
ADDITIONAL TESTING:
The SPC is composed of several parts which should be verified by testing and visual inspection during spark plug replacement or if they are suspect of causing a misfire or vibration. Because these connections are subject to high voltage (15,000+ volts) a bad connections can burn and arc damaging components.
With an ohm meter set to K ohms, insert the test leads into each end of the cap. It should measure 10K ohms. Internal to the cap is a resistor, spring, plug lock, and self threading cable connector. If any of these component have corrosion, arcing, or burning, they should be replaced. Also, the FSM does not list a limit. Mine all measured 10.7 ~ 10.8K ohms.
The resistor spark plugs are supposed to measure 5.0K ohms. My used CR9EK's measured ~ 4.0K ohms each.
COMPONENTS:
On top of my meter you see the spring, ceramic resistor, locking insert (locks Cap to Plug), and the end of the cap body.
Spark Plug Cap (SPC) Drawing:
Actual components internal to cap:
Note: use a flat head screw driver to remove the locking insert.
SPECULATION/ROOT CAUSE:
In this photo the wires spiral wound core was pushed off to one side and the this cap spun freely with no resistance to turning. I cannot prove it, but if you read about inductance and capacitance you see were a tiny change can change the timing of how a coil charges and discharges. It may be milliseconds/microseconds, but it correlates to all if the cylinders not being fired at the same time and this induces the vibration we feel.
HOW WAS THIS DISCOVERED:
I found that the spark plug wire to cap had gotten loose as described here. Although it didn't create a misfire or make the bike run bad (it ran great), it did make a harmonic vibration across all RPMs which rules out throttle body sync. This vibration was increasing so I went for ONE CHANGE and that was to remove the four plug caps from the head and inspect how the high tension lead was seated to the caps. I DID NOT TOUCH ANYTHING ELSE, JUST THE SPC/s & HTS's.
That's when I found the HTL was no longer tight in the SPC. At first I thought this condition added resistance to the junction and it may very well do that. However, the spark plug and the cap assembly account for 13 to 16,000 ohms of resistance THUS IT IS VERY UNLIKELY that a copper wire against a brass screw has high resistance. i.e. more than 10 ohms total. It is MORE likely there is capacitance altering the coils saturation time (charge rate). Remember this is a waste spark system and one coil is responsible for two cylinders. The capacitance may actually alter when the spark arrives thus inducing harmonic vibrations to the firing as it out of time ever so slightly.
PS - I found that one wire being loose can cause a noticeable vibration!! In the last event, cap #4 (spun freely w/out resistance). Before that it was #2 about 2000 miles ago.
SPARK PLUGS:
Check the gap on your plugs and do not Exceed the Recommended gap. If using conventional carbon plugs (CR9EK side fire or CR9E End Fire) the gap should be set to less than the maximum as it opens as it wears. See picture below.
Spec: 0.024–0.028 in (0.6–0.7 mm)
**********************************
PRECIOUS METAL PLUGS AND GAPING:
Before installing spark plugs, the gap must be checked as the plug has many other applications (not just the FZ6 engine) which means the gap MAY NOT BE SUITABLE for this vehicle!
If the gap is too large it can be the cause of the poor acceleration upon re-wetting the intake.
Bottom line: the plugs must be gaped to meet the requirements of the engine they are installed in.
Spec: 0.024–0.028 in (0.6–0.7 mm)
**********************************
SPARK PLUG TORQUE SPEC:
18 Nm (1.8 m·kg, 13 ft·lb)
**********************************
Used Plugs ~ 13,000 miles and Excessive Gap from Wear:
Note: Plugs gap is opening up as material wears away (2 and 3).
**********************************
THIS DOES NOT FIX: vibrations induced by poor drive chain maintenance, worn sprockets, or kinky chains.
SEE "How to string align your rear wheel!!" for chain and wheel alignment issues: http://www.600riders.com/forum/how-to-s-/40463-how-string-align-your-rear-wheel.html
It is recommended to perform this when changing spark plugs and before performing a Throttle Body Sync.
**********************************
Off Topic but related to ignition testing and from post 33 of this thread. If anyone wants to see the coils unleash on the plug, Place the meter into Diagnostic mode and ground the spark plug bodies.
**********************************
EDITS:
2014-11-08 Added pictures, Zip-Tire and lower the radiator core
2014-05-27 Added link to String Align Rear Wheel
2014-05-09 Check those precious metal plugs
2014-04-11 Embed post 33
2014-04-11 FIX BROKEN LINKS! errr....
2014-03-31 Fix broken links
2013-09-04 Clarify actions, list order of operation
**********************************
WHAT IS THE CAUSE?:
The the Spark Plug Cap (SPC) threads into the High Tension Lead (HTL) wire core using a brass screw with a conventional clockwise thread. As the wire ages, the insulation around the wires core may relax allowing the copper core wire to move away from the caps brass screw. This loss of connection translates to vibrations across throughout mid to upper RPM's. Remember this is a waste spark ignition and each coil is responsible for 2 spark plugs firing and a poor connection at either plug can alter the timing, energy, or duration of the spark to a cylinder! We feel this as harmonic vibration in the bars and seat. The good news is, its easy to fix!
IMO - unless the wires core is completely broken, it IS NOT responsible for a misfire! That is, the engine will start, idle, and accelerate fine. But the chassis may have harmonic vibration from about 4K on up.
HOW TO CHECK IT AND CORRECT IT:
- From the left side, remove the two 10 mm bolts holding the radiator and let it settle on the hoses. Be careful of the lower bracket hitting the radiators CORE! More info here ->See post 6 for more pictures.
- Remove spark plug cap #4 (right side). PULL ON THE THE CAP BODY, NOT THE WIRE!!!
- With the cap free in hand, hold the HTL (wire) and gently rotate the CAP ASSEMBLY CLOCKWISE. The cap may turn about a half turn on the wire and **should become snug and resist turning.** If the cap SPINS ON THE WIRE IT NEEDS REPAIRED!
- REPAIR THE WIRE: If the cap spins with no resistance to rotation, unscrew it by rotating the CAP counter clockwise while holding the wire. Using a pair of sharp side cutting pliers, cleanly cut off 1/4" (6 mm) from the HTL.
- Using small pick, fan out the copper wire strands into a 360° pattern. Do not bend them repeatedly!
- FAN OUT WIRES:
- Push the SPC onto the wire and turn it clockwise until its snug.
- Add a ZIPTIRE to the boot! Because the wires are strained once fitted to the engine, the ZIPTIE will extend the interval before coming loose again.
- Proceed to next cap and remove it for inspection. I find it easier to leave the caps out until all wires are verified/repaired. Turn the bars and hang them over the radiator.
*** ADDITIONAL TESTING; If you have a DMM (Digital multimeter) and want to test the resistor internal to the SPC, see section below for additional testing before installing the cap onto the wire.
SPC INSTALLATION INTO VALVE COVER:
- Starting on the left side of the engine, insert SPC #1. You should feel and hear the lock on the cap engage the spark plugs conductor. The dust seal should simultaneously seat on the valve cover. If the SPC pops back up any amount after seating it, remove the SPC and move the dust seal up the body towards the HTC.
- Firmly Seat the SPC onto the plug.
- Firmly Seat the dust seal onto the the valve cover. Confirm it seals 360 degrees.
- Proceed to next SPC.
ADDITIONAL TESTING:
The SPC is composed of several parts which should be verified by testing and visual inspection during spark plug replacement or if they are suspect of causing a misfire or vibration. Because these connections are subject to high voltage (15,000+ volts) a bad connections can burn and arc damaging components.
With an ohm meter set to K ohms, insert the test leads into each end of the cap. It should measure 10K ohms. Internal to the cap is a resistor, spring, plug lock, and self threading cable connector. If any of these component have corrosion, arcing, or burning, they should be replaced. Also, the FSM does not list a limit. Mine all measured 10.7 ~ 10.8K ohms.
The resistor spark plugs are supposed to measure 5.0K ohms. My used CR9EK's measured ~ 4.0K ohms each.
COMPONENTS:
On top of my meter you see the spring, ceramic resistor, locking insert (locks Cap to Plug), and the end of the cap body.
Spark Plug Cap (SPC) Drawing:
Actual components internal to cap:
Note: use a flat head screw driver to remove the locking insert.
SPECULATION/ROOT CAUSE:
In this photo the wires spiral wound core was pushed off to one side and the this cap spun freely with no resistance to turning. I cannot prove it, but if you read about inductance and capacitance you see were a tiny change can change the timing of how a coil charges and discharges. It may be milliseconds/microseconds, but it correlates to all if the cylinders not being fired at the same time and this induces the vibration we feel.
HOW WAS THIS DISCOVERED:
I found that the spark plug wire to cap had gotten loose as described here. Although it didn't create a misfire or make the bike run bad (it ran great), it did make a harmonic vibration across all RPMs which rules out throttle body sync. This vibration was increasing so I went for ONE CHANGE and that was to remove the four plug caps from the head and inspect how the high tension lead was seated to the caps. I DID NOT TOUCH ANYTHING ELSE, JUST THE SPC/s & HTS's.
That's when I found the HTL was no longer tight in the SPC. At first I thought this condition added resistance to the junction and it may very well do that. However, the spark plug and the cap assembly account for 13 to 16,000 ohms of resistance THUS IT IS VERY UNLIKELY that a copper wire against a brass screw has high resistance. i.e. more than 10 ohms total. It is MORE likely there is capacitance altering the coils saturation time (charge rate). Remember this is a waste spark system and one coil is responsible for two cylinders. The capacitance may actually alter when the spark arrives thus inducing harmonic vibrations to the firing as it out of time ever so slightly.
PS - I found that one wire being loose can cause a noticeable vibration!! In the last event, cap #4 (spun freely w/out resistance). Before that it was #2 about 2000 miles ago.
SPARK PLUGS:
Check the gap on your plugs and do not Exceed the Recommended gap. If using conventional carbon plugs (CR9EK side fire or CR9E End Fire) the gap should be set to less than the maximum as it opens as it wears. See picture below.
Spec: 0.024–0.028 in (0.6–0.7 mm)
**********************************
PRECIOUS METAL PLUGS AND GAPING:
Before installing spark plugs, the gap must be checked as the plug has many other applications (not just the FZ6 engine) which means the gap MAY NOT BE SUITABLE for this vehicle!
If the gap is too large it can be the cause of the poor acceleration upon re-wetting the intake.
There is a right way and wrong way to verify the correct the plugs gap. Yes, the wrong way could damage a precious metal plug. Using the proper tools for the job reduces the risk of damage.
Regarding application:
NGK Spark Plugs USA
How to Gap a Plug (precious metal specific):
NGK Spark Plugs USA
Regarding application:
NGK Spark Plugs USA
How to Gap a Plug (precious metal specific):
NGK Spark Plugs USA
Bottom line: the plugs must be gaped to meet the requirements of the engine they are installed in.
Spec: 0.024–0.028 in (0.6–0.7 mm)
**********************************
SPARK PLUG TORQUE SPEC:
18 Nm (1.8 m·kg, 13 ft·lb)
**********************************
Used Plugs ~ 13,000 miles and Excessive Gap from Wear:
Note: Plugs gap is opening up as material wears away (2 and 3).
**********************************
THIS DOES NOT FIX: vibrations induced by poor drive chain maintenance, worn sprockets, or kinky chains.
SEE "How to string align your rear wheel!!" for chain and wheel alignment issues: http://www.600riders.com/forum/how-to-s-/40463-how-string-align-your-rear-wheel.html
It is recommended to perform this when changing spark plugs and before performing a Throttle Body Sync.
**********************************
Off Topic but related to ignition testing and from post 33 of this thread. If anyone wants to see the coils unleash on the plug, Place the meter into Diagnostic mode and ground the spark plug bodies.
HOW TO TEST YOU COILS AND ECM:
Our bikes have the option of being placed into a diagnostic mode that will trigger each of the coils to deliver 5 sparks. You can use this to test the coils and look for arc over without the engine actually running so you can HEAR electrical leakage should it exist.
** YOU MUST insert a spark plug. **
** YOU MUST ground the body of the spark plug to the engine block. **
An alligator clip to the plugs body and the other end clamped to a bare metal engine surface should be adequate.
DIAGNOSTIC MODE, Setting the diagnostic mode
1. Turn the main switch to “OFF” and set the engine stop switch to “RUN”.
2. Disconnect the wire harness coupler from the fuel pump (Green Connector).
3. Simultaneously press and hold the “SELECT” and “RESET” buttons, turn the main switch to “ON”, and continue to press the buttons for 8 seconds or more.
4. Press the “SELECT” button to select the diagnostic monitoring mode “dIAG”.
5. After selecting “dIAG”, simultaneously press the “SELECT” and “RESET” buttons for 2 seconds or more to execute the selection.
6. Set the engine stop switch to “OFF”.
7. Select the diagnostic code number that applies to the item that was verified with the fault code number by pressing the “SELECT” and “RESET” buttons ((30 or 31)).
8. Verify the operation of the sensor or actuator.
• Sensor operation
The data representing the operating conditions of the sensor appears on the trip LCD.
• Actuator operation
Set the engine stop switch to “RUN” to operate the actuator.
If the engine stop switch is set to “RUN”, set it to “STOP”, and then set it to “RUN” again.
9. Turn the main switch to “OFF” to cancel the diagnostic mode.
NOTE:
• To decrease the selected diagnostic code number, press the “RESET” button. Press the “RESET” button for 1 second or longer to automatically decrease the diagnostic code numbers.
• To increase the selected diagnostic code number, press the “SELECT” button. Press the “SELECT” button for 1 second or longer to automatically increase the diagnostic code numbers.
Sensor code from operation table:
30: Ignition coil #1, #4
31: Ignition coil #2, #3
See FSM for other sensors which can be tested in diagnostic mode.
2008 FZ6 Coil:
FWIW: Near the Spade is a "+" and "-" embodied in the housing. RED to PLUS SIDE!
**********************************
EDITS:
2014-11-08 Added pictures, Zip-Tire and lower the radiator core
2014-05-27 Added link to String Align Rear Wheel
2014-05-09 Check those precious metal plugs
2014-04-11 Embed post 33
2014-04-11 FIX BROKEN LINKS! errr....
2014-03-31 Fix broken links
2013-09-04 Clarify actions, list order of operation
**********************************
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