Vibration! A cure for bad vibrations, Spark Plug Caps!!

I've recently found that my number 1 spark plug cap is very loose and firing intermittently, causing a rough, surging idle and slight loss of power. When I pull the cap off the plug, the idle immediately smooths out. I've ordered one of these "5VX-82370-00-00 PLUG CAP ASSY " to replace it with, but now I'm wondering if my problem is actually at the coil...

Is it simple to swap the old plug cap for the new one? Or does the coil need to be opened up?

outasight20 said:

I've recently found that my number 1 spark plug cap is very loose and firing intermittently, causing a rough, surging idle and slight loss of power. When I pull the cap off the plug, the idle immediately smooths out. I've ordered one of these "5VX-82370-00-00 PLUG CAP ASSY " to replace it with, but now I'm wondering if my problem is actually at the coil...

Is it simple to swap the old plug cap for the new one? Or does the coil need to be opened up?

Click to expand...

The spark plug cap simply screws on clockwise.

Just make sure there's no arcing (blackish tint) at the end of the wire. If so, trim the wire down about 1/4".

Spread the center wires out and screw the new cap with the point of the cap dead center of those main, lead wires...

Done

TownsendsFJR1300 said:

The spark plug cap simply screws on clockwise.

Just make sure there's no arcing (blackish tint) at the end of the wire. If so, trim the wire down about 1/4".

Spread the center wires out and screw the new cap with the point of the cap dead center of those main, lead wires...

Done

Click to expand...

Thanks,

Won't have a chance to look at this until the weekend. I recall when changing my plugs a few days ago that there was some white marking inside the spark plug cap for cylinder 1. This indicated to me some sort of arcing or shorting. I will keep this updated with my results and post pictures if I find anything worthwhile.

outasight20 said:

Thanks,

Won't have a chance to look at this until the weekend. I recall when changing my plugs a few days ago that there was some white marking inside the spark plug cap for cylinder 1. This indicated to me some sort of arcing or shorting. I will keep this updated with my results and post pictures if I find anything worthwhile.

Click to expand...

Usually that white powder on the plugs body is just from water intrusion reacting with the alloy head and plugs plating. Its all on the outside so it should not cause an issue unless your plug well is in fact filling with water.

The first post should cover most everything that needs checking. Do remember that exceeding the OEM Spec for Gap can cause misfire issues. To date I can't say anyone has specifically had an actual coil failure but these bikes are aging. If when running you can look up and see arcing (RUN ENGINE IN THE DARK) from the wires or coil body it would be wise to replace its arc over voltage degrades the wires and coil. In short we need more info so report back.

If you don't currently have or own a DMM - order something like this and you can test the caps internal resistor and the plug and lost of other items. Newegg.com - New DT-9205A Digital Voltmeter Ammeter Ohm Test Meter Multimeter A/D Converter

$20.00 shipped
Technical data:
Basic function Range Basic accuracy
DCV 200mV/2V/20V/200V/1000V ±(0.5%+2)
ACV 2V/20V/200V/700V ±(0.8%+3 )
DCA 2mA/20mA/200mA/20A ±(1.4%+2)
ACA 2mA/20mA/200mA/20A ±(1.8%+3)
Resistance 200O/2kO/20kO/200kO/2MO/20MO/200MO ±(0.8%+2)
Capacitance 2nF/20nF/ 200nF/2uF/200uF ±(4.0%+5)
Frequency 2kHz/20kHz ±(2.5%+5)

Plugs arrived early and bike is off the operating table.

• NGK Iridium plugs installed
• Gaps checked with feeler gauge- all within spec
• Wires twisted snug onto the caps
• Used only di-electric grease

It wasn't such a PITA despite big hands. A caveman could do it.

Bike fired up immediately. After warm-up vibrations at the handlebar appear reduced. So far so good. Test ride soon.

Update: Vibrations are significantly down. No longer irritating at all and didn't notice while riding at the bar or pegs. Thanks. Rep inbound Randy. :rockon:

darius said:

Update: Vibrations are significantly down. No longer irritating at all and didn't notice while riding at the bar or pegs. Thanks. Rep inbound Randy. :rockon:

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Thanks for the Rep and glad that helped! Does it Wheelie now? Blah

Surely you must all know me well enough by now that this won't be out of place - So how many miles on the OLD plugs and what did they look like? Wanna see the Whites and Electrode only! :thumbup:

FinalImpact said:

Thanks for the Rep and glad that helped! Does it Wheelie now? Blah

Surely you must all know me well enough by now that this won't be out of place - So how many miles on the OLD plugs and what did they look like? Wanna see the Whites and Electrode only! :thumbup:

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I'm assuming they were the factory plugs so just 6k. They were tan just like your opening post.

Curious -- I've read about vibrations from the FZ6 since I started following this forum.

Define vibrations -- this is my first motorcycle, and I assumed a little "buzz" from the handlebars was just a thing with riding bikes. Sometimes it numbs my hands, but I figure that's just me gripping the bars too tightly, I sometimes get a little buzz from the foot pegs, but it's not constant.

Thx,
Nthdegreeburns

nthdegreeburns said:

Curious -- I've read about vibrations from the FZ6 since I started following this forum.

Define vibrations -- this is my first motorcycle, and I assumed a little "buzz" from the handlebars was just a thing with riding bikes. Sometimes it numbs my hands, but I figure that's just me gripping the bars too tightly, I sometimes get a little buzz from the foot pegs, but it's not constant.

Thx,
Nthdegreeburns

Click to expand...

Opinions will vary so lets weed out a few things.
Body Position:
Hands can go numb for a few reasons. Death grip being #1 followed by pinched nerves #2. The first is mental, don't do it. When the bike is setup right and the rider competent and relaxed you can float your hands on the grips. This won't correct the bad angle if you don't fit the bike. Sling your arms out straight 3 times and look at the angle of you wrists. Up/down/left/right. When on the bike they should also come to that same "slung out, natural position" as in not bent at an odd angle or theres a good chance your nerves will be pinched if your wrists are pointed at excessive angles for prolonged periods of time. Correct the bike to fit you.

Vibrations from engine (bike NOT moving):
As stated before, this does not cure drive-train vibrations. A simple example is this; if your mirrors are oscillating from harmonics while stationary a tune up and/or following this thread may help. FWIW: I have a faired bike and the mirrors useful visibility is only limited by my eyes. They do not vibrate making it blurry. They DID before I performed this procedure and I could hardly see behind me!
Also, while stationary your pegs and butt should not vibrate either. If you're familiar with a tuning fork, the vibration is like that - its frequency is not that of the engine RPM per say but a harmonically induced vibration that makes the entire bike feel like a vibrator!

Vibrations while moving:
The discernible difference here is the frequency. Tire roundness, tire balance, chain condition and alignment as well as disc brake vibes all vary with road speed. Some only occur at certain speed while the engine tune vibrations are very constant throughout all vehicle speeds. Especially when induced by the spark plug wire. However a Throttle Body imbalance would likely only be present from idle to say 3500 RPM or so and then go away. This issues is present throughout the entire RPM range REGARDLESS of road speed!

In short; harmonic vibrations that make all contact points where your body touches the bike numb or vibrate - something is wrong and it is NOT normal.

Got the new plug cap in. I checked the tightness of the old cap to the ignition wire and it was a bit loose. However more importantly the inside of the old plug cap looked like it had seen better days. See picture comparing old to new. Bike is back to normal after replacing plug cap.

outasight20 said:

Got the new plug cap in. I checked the tightness of the old cap to the ignition wire and it was a bit loose. However more importantly the inside of the old plug cap looked like it had seen better days. See picture comparing old to new. Bike is back to normal after replacing plug cap.

Click to expand...

That's looking pretty rough there! New plugs too and how exactly was it running? i.e. - tell tale signs of disfunction.

Thanks

I didn't ride the bike before changing out the plug cap, but I did let it idle after doing my valve check and plug replacement. The idle would surge up and down about 300-400 RPM. When I unplugged cylinder 1, the idle stabilized. When I replaced my plugs, I initially forgot to remove the silver cap on the threaded end and tried forcing the number 1 plug cap into place before realizing it wasn't happening. This is what really did it in I think. Although it was loose when I removed it prior to the valve job.

FinalImpact said:

When on the bike they should also come to that same "slung out, natural position" as in not bent at an odd angle or theres a good chance your nerves will be pinched if your wrists are pointed at excessive angles for prolonged periods of time. Correct the bike to fit you.

Click to expand...

I KNOW that the mental strangling of the handlebar is in play. I will need to test the position issue. I hadn't thought of that. Since you're working on that FAQ for basic maintenance, I dunno if you wanna include basic mods e.g. the differences between all the different bars people seem to change out on the FZ6.

FinalImpact said:

FWIW: I have a faired bike and the mirrors useful visibility is only limited by my eyes. They do not vibrate making it blurry. They DID before I performed this procedure and I could hardly see behind me!

Click to expand...

Checked this -- no such vibrations while the bike is idling. So that's not an issue.

FinalImpact said:

Some only occur at certain speed while the engine tune vibrations are very constant throughout all vehicle speeds. Especially when induced by the spark plug wire. However a Throttle Body imbalance would likely only be present from idle to say 3500 RPM or so and then go away. This issues is present throughout the entire RPM range REGARDLESS of road speed!

Click to expand...

OK -- this makes more sense. Maybe some throttle body imbalance and/or occasional conditions that match up. The numbing / buzzing in the handlebars OR footpegs sometimes happens in a narrow band of RPMs, so perhaps some tuning is in order.

Bummer -- if you wanna replace these assemblies, you have to drop $50 or so for each...

5VX-82370-00-00 Yamaha Plug Cap Assy.

:-(

nthdegreeburns said:

I KNOW that the mental strangling of the handlebar is in play. I will need to test the position issue. I hadn't thought of that. Since you're working on that FAQ for basic maintenance, I dunno if you wanna include basic mods e.g. the differences between all the different bars people seem to change out on the FZ6.

Checked this -- no such vibrations while the bike is idling. So that's not an issue.

OK -- this makes more sense. Maybe some throttle body imbalance and/or occasional conditions that match up. The numbing / buzzing in the handlebars OR footpegs sometimes happens in a narrow band of RPMs, so perhaps some tuning is in order.

Click to expand...

Perhaps I should have said, not every bike will do these but these are some traits and now its dependent upon how far along the issue has progressed.

One day i noticed the grease wearing off my rear sprocket on one side of the rollers only. This was like a hint that the wheel may not be aligned perfect. From this, I did the string align and that knocked down some speed related vibes.
>>CLICK PIC>>



WORK THAT REDUCED VIBES:
- plug wires (reduced vibes across all RPMs)
- rear wheel alignment for drive chain (road speed vibe reduction)
- Chain maintenance - Clean, Clean, CLEAN and lots of Lube 400 miles max interval
- draining Mobile One oil (2000 miles or less) I couldn't take the vibes!! I know millions will say I'm full of BS, but I'm saying I ROUTINELY CHANGE ONE THING AT A TIME and I CHANGED THE OIL AND THE VIBES WERE REDUCED! Hey I'm not the only one that dumped that bike specific expensive product throwing away money to know if that was it. It was!

nthdegreeburns said:

Bummer -- if you wanna replace these assemblies, you have to drop $50 or so for each...

5VX-82370-00-00 Yamaha Plug Cap Assy.

:-(

Click to expand...

Why do you want to replace them - are they bad? Have you checked them?

Finally took the bike out for a longer ride (2 hours on the countryside and some highway after that just to test for vibrations).

Having checked valve clearence + throttle body sync I also fixed this. They cap/cable connection was waaaaay loose. I couldn't almost just pull the 2 parts form eachother with ease.

Haven't been on my bike for 6 months so hard to say just how worse they where before - but I am pretty sure its better now. No tingeling feeling in my right hand unless I really squeeze the handle for a longer period - and really who does that unless it's track day!?
I do feel noticable vibrations at higher RPM (from midrange and up) but I am sure they are just not as awful as before. It sure wasn't annoying when "cruising" with 150km/t for a short while... so I can't complain

I guess I have to conclude that I can't be 100% sure that this was the one and only solution for annoying vibrations (having done more than one fix). But it must have helped... it's an easy check/fix - just do it !!! :thumbup:

FinalImpact said:

So, have you had a chance to ride this and did it help reduce the vibes?

Tks!

Click to expand...

After 7 months of winter hibernation and servicing the bike passed it's MOT with flying colours this morning So I've had the chance to ride about 50 miles so far and the amount of vibration has definitely been reduced - another success! Also a slight hesitation in lower rev's when the engine was cold (which I attributed to the S1's snatchy fuel injection) seems to have gone.

This spark plug cap fix solved a horrendous year long saga of buzzing for me! I was It started over a year ago when the buzzing crept in...the worst vibrations were limited to 6k to 8k rpm, and nothing before 5k. Ironically FinalImpact posted a link to this thread last year on my problem thread, but I must have resigned to live with it by that point...I was very frustrated and had checked a lot of other potential issues

Last week I had random misfires to piston 1 and 4, and in response I found this thread. Taking the time to read through it, I gave the fix a shot. I tore the bike apart, trimmed and adjusted the connection to the caps, and took it for a ride. Viola! Fixed! Vibrations gone. It's amazing, I had forgotten how beautiful the engine sounds at that sweet spot!

After reading through this thread, the vibrations I had felt could only be described as "harmonic", a term which I've heard a few times here. If you watch the video I posted on my problem thread you can hear the frequency of the vibration slowly change as rpms rose above 5500:

http://www.600riders.com/forum/garage-mechanical-help/48537-loud-buzzing-7000rpm-up-video.html

A year ago I didn't fully grasp how the coil>spark plug>engine process worked, and I couldn't associate it with causing vibrations outside of something mechanical being broken. The harmonic nature of the vibes could have been a clue...it wasn't clunking, rattling, but vibrating.

I also was not as confident as I am now with ripping my bike apart to solve problems. Electrical issues are the most daunting for me...if it was just part of my fairing that was loose, that would have been easy...even if it had been chain noise, aligning the wheel is quite simple compared to pulling wires apart and measuring this alien unit called ohms.

In retrospect, I'm really happy all this happened. I learned a ton about how my bike actually operates, I gained confidence in troubleshooting electrical issues, and ultimately I fixed my bike which boosts morale no matter where I am in life. Blah

I can't thank everyone on this awesome forum enough, especially [MENTION=15974]FinalImpact[/MENTION] who not only provided extremely valuable information, but truly understands that:

:needpics: