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Changing spark plugs

touring03

Member
Member
I have watchwd a number of videos on changing plugs on the C14, they all show removal of the side bodywork and accessing the plugs from the side of the engine, would it not be easier to remove the gas tank and access all the plugs from above the engine?
 
I have watchwd a number of videos on changing plugs on the C14, they all show removal of the side bodywork and accessing the plugs from the side of the engine, would it not be easier to remove the gas tank and access all the plugs from above the engine?
C-14 frame is solid above the engine, no immediate access from the tank.

Wayne, Carol & Blue
 
I agree with 2andblue.

The C-14 has a very powerful engine and a traditional frame just can't get the job done. On a lower powered bike there is a strut or beam at the top of the frame that the tank straddles, but NOT on this beast. The frame above the engine looks more like a cage to better support the beast under the tank and the bike being fed power by that monster. If the bike had a more "traditional" frame the tank would be massive because it is quite wide, it just isn't all that deep due to the big frame work under it. The side access is the best you can do. Wait until you do the valves, you're gonna just love all that access - NOT!

Jon B
 
It is also quite a trick to synchronize the throttle bodies. I tried the technique of trying to attach hoses after pulling the tank and inlet boots. Just too tight a space and I gave up until I do the next valve check.
 
It is also quite a trick to synchronize the throttle bodies. I tried the technique of trying to attach hoses after pulling the tank and inlet boots. Just too tight a space and I gave up until I do the next valve check.
I wouldn’t even think of performing this without the subframes off, access is too tight. Valve check is THE perfect time since you’re already in there and then of course the valve timing is now reset and air flow should be synced.

Not at all saying you should not do it, as I can feel the benefit in smoothness (probably small amount of efficiency too) but I wouldn’t sweat it much. The C-14, especially when compared to other machines, holds a tight and level air flow. C-14 usually only needs minor adjustments - the factory seems to do a good job here and then there’s the engineering as well.

Wayne, Carol & Blue
 
She is running well and I have no complaints. Will be riding from West Michigan to the middle of Pennsylvania in a couple weeks. I just added a throttle lock to help my wrist on longer stretches. Should be a great ride!
 
I guess someone needs to explain to me how putting the valves in spec requires a carb or throttle body sync.
Steve
...I feel like you're trolling us, Steve, but for the good of the masses I'll share what made it 'click' for me many years ago:

You're not trying to sync the throttle body/carbs with each other so the butterflies are in the exact same place. You're syncing the cylinder output at a given throttle position so that each cylinder is producing approximately the same amount of vacuum (which translates into approximately the same power output since these are just gas-powered air pumps, after all...)

In other words, at a specific RPM/throttle opening, you're finding the cylinder with the lowest vacuum and closing the butterflies on the other carbs/TBs to lower the vacuum on those cylinders to match.

This has the benefit of both increasing the smoothness, especially of a 4-cyl engine, but also keeping the cylinders from fighting each other with one or two cylinders "dragging" the lower output cylinder(s) along.

When you change valve clearances (to get them back in spec) you are changing the vacuum/output of each cylinder, generally for the better, but this change may warrant adjustment of the TBs... thankfully it's pretty straightforward to sync them with the right tools.
 
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I guess someone needs to explain to me how putting the valves in spec requires a carb or throttle body sync.
Steve
Prior to the quoted comment - nobody stated that a throttle body sync was required after the periodic valve clearance check / adjustment, well other than Kawasaki's periodic maintenance schedule discussed a bit more below and not mentioned until just now.

Kawasaki engineers have built into the periodic scheduled maintenance throttle body synchronization at the mid-point between valve clearance checks (7,600 miles) and again at the periodic valve clearance adjustment (15,200 miles). Some further comments were added in an above post why these synchronizations are scheduled and why / when.

I personally would not bother with the throttle body synchronization of the C-14 every 7,600 miles as per the periodic maintenance schedule. Same goes for the spark plugs change interval at the same 7,600 cadence, seems a bit excessive to me...

At the time of valve clearance check / adjustment (15,200 miles) there is an accumulation of natural wear and of course the changing of valve clearance / open/close if only by minuscular amounts will effect air flow - thus the scheduled synchronization check is potentially beneficial. On the C-14 I have no doubt many NEVER synchronize the throttle bodies to very little or no perceivable detriment... I do know there is a positive effect thus I perform the synchronization at the 15,200 interval or thereabouts in alignment with the valve clearance check / adjustment.

Unsure if that helps @Steve in sunny Fla ?

Separately, to the original poster @touring03, did the comments on the frame / accessibility clarify the question on spark plug change and access thereof? Unfortunately, there's no magic bullet here on changing the spark plugs. How many miles on your machine and/ or how many miles since spark plugs changed last? See my comment just above, personal choice of course, but I would not mess with the spark plugs at the aggressive change internal (7,600 miles) that Kawasaki recommends. Note: I also have the wiring for a Healtech Quickshifter and the unit itself nested in the engine bay area so that adds another level of fun when dressing the machine down for a spark plug change, the fun is worth the hassle though!

Wayne, Carol & Blue
 
So lets assume an engine has properly adjusted valves and the throttle bodies are properly synced. Then the valves go out of spec, and are brought back in spec by another proper valve adjustment. Should the throttles still be synced?Why would a throttle body sync matter at that point?
Steve
 
I just got into the habit of synching the cards when I did my valves on the C-10, I think maybe once I needed to make an adjustment, I always thought it was a common practice. I was there, it took 5 minutes, what could it hurt?
 
So lets assume an engine has properly adjusted valves and the throttle bodies are properly synced. Then the valves go out of spec, and are brought back in spec by another proper valve adjustment. Should the throttles still be synced?Why would a throttle body sync matter at that point?
Steve
Fair question for sure.

If in a perfect world where all wear is 100% equal and valve job done to exacting precision then a sync would I suppose theoretically not be needed.

Given that cylinder walls, rings, valve seats, valves can wear differently, I would suppose that is why Kawasaki recommends a synchronization as frequently as they do - every 7,600 miles…

Wayne, Carol & Blue
 
So what happens to the sync if a plug quits firing?
Steve
Nothing - Throttle Body synchronization is mechanical and remains the same.

Good subject, but we've drifted deeply into another topic from OP posted subject. If there are further questions or thoughts @Steve in sunny Fla please start a new thread on Throttle Body Synchronization where the group can delve deep into theory, cadence, benefit, process dos and don'ts can and topic can be easily searched later.

@Steve in sunny Fla possibly start one for the C-10 and C-14 since both have (same theory) different processes. @Steve in sunny Fla, your content has been useful for many and without doubt this could be helpful - why not a video on this topic?

Thank You,
Wayne
 
I guess someone needs to explain to me how putting the valves in spec requires a carb or throttle body sync.
Steve
So lets assume an engine has properly adjusted valves and the throttle bodies are properly synced. Then the valves go out of spec, and are brought back in spec by another proper valve adjustment. Should the throttles still be synced?Why would a throttle body sync matter at that point?
Steve
So what happens to the sync if a plug quits firing?
Steve

Pretty sure the people on here were just saying that you should do a throttle body sync at the same time as the valves, since its easy to get to both jobs since what's got to come off the bike is about the same. So it just makes sense to do it while you're in there. Don't think its much more than that

But what do I know? I'm just some tech geek with a C10, and DEFINITELY no mechanic or engineer. I fix computers, not motorcycles, so take it with a grain of salt....

In any case, I agree with Wayne about getting back to what the OP was posting about.

To the OP: Do you have a factory service manual? If not, I'd get one. They're invaluable for these bikes. And thanks for the conversation starter! This is good, especially at driving engagement. 😎

-Z
 
Nothing - Throttle Body synchronization is mechanical and remains the same.

Good subject, but we've drifted deeply into another topic from OP posted subject. If there are further questions or thoughts @Steve in sunny Fla please start a new thread on Throttle Body Synchronization where the group can delve deep into theory, cadence, benefit, process dos and don'ts can and topic can be easily searched later.

@Steve in sunny Fla possibly start one for the C-10 and C-14 since both have (same theory) different processes. @Steve in sunny Fla, your content has been useful for many and without doubt this could be helpful - why not a video on this topic?

Thank You,
Wayne
I did videos on this already over 10 years ago. Still on you tube.

A poster brought up throttle sync and then that was tied in your post to valve adjustment. My questions were designed to get people to think, not just parrot. Regardless, message received, lets get back to replacing spark plugs.


Steve
 
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Are spark plugs for the C-14 readily available at most places made by most makers at most normal quantities? The reason I ask is almost every time I go to buy plugs, they are some sort of rare, unobtainable, unknown substance, size/color/variant only made on odd numbered years at a small plant near Nikko Japan, you have to put an order in and they cost $24 a piece and it takes 4 months to get them.:)

I'm not embellishing too much here, it just seems to happen to me more often.
 
The C14 plugs are readily available online, through a local motorcycle shop/dealer, or some guy named Murph and his kits... :ROFLMAO:

But I'm not sure if you can swing down to Autozone and pick them up......... Actually I just looked and they're readily available right now. NGK #6289 or CR9EIA-9. So as of now it shouldn't be too hard to find them locally. And, as indicated in a thread a few days ago, if you order from Murph, he'll ship them right before you order them so they arrive near-instantly.

But that's not always the case, the non-resistor plugs for my old '80/'82 XJ650 I used to buy at Napa, $2.xx apiece, but NGK does not make them anymore, I'd have to buy the resistor plug equivalent and change my plug caps over to non-resistor style. Thankfully I have a surplus of old plugs and a pneumatic spark plug abrasive cleaner that works well to remove any soot. And they're just copper plugs so I don't need to worry about degrading the platinum/iridium layer because there is none!
 
NGK has dropped ALOT of plugs, and all their plug boots. There have been some counterfeit NGK plugs floating around, not sure if they have that mess cornered now or not .
 
I did videos on this already over 10 years ago. Still on you tube.

A poster brought up throttle sync and then that was tied in your post to valve adjustment. My questions were designed to get people to think, not just parrot. Regardless, message received, lets get back to replacing spark plugs.


Steve

Hey, Steve. I'm glad you're here to help us think about this stuff. Though it's too bad you've stopped supporting the C10 in anyway shape or form:

1720635195644.png

Your older videos are great! A lot of sage knowledge. Hope you keep those videos/articles up for all the young whippersnappers that are buying up C10s as retro bikes. And I hope you continue supporting the C14 for the foreseeable future; that stuff really helps the community, and we all know you're about community. You wouldn't be trying to get us to "think, not parrot" if you weren't!

😎

-Z
 
Thanks, Nova, just setting my ducks up for when I do the big first initial work and don't want the kind of surprises you talk about with plugs. I seem to gravitate to vehicles and products that are either at the end of the line of sales or design or discontinued support. BTW, I had a '70 Nova, looked good, sounded good, manual tranny, but it wasn't fast at all, not with a 307.
 
When it comes to iridium or double platinum in an NGK or Denso plug usually not required, and if you do it is best to check and perform the procedure with a rounded wire style gapper tool. Since the Internet is a world of hundreds of responses of how or why I copied and pasted NGK Technical writing and listed the link right below it.


5 Things You Should Know About Spark Plugs​

1. Anti-seize
NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize.
Anti-seize can act as a lubricant, altering torque values up to 20 percent, and increasing the risk of spark plug thread breakage and/or metal shell stretch. Thread breakage can sometimes involve removing the cylinder head for repair. Metal shell stretch changes the heat rating of the spark plug and can result in serious engine damage caused by pre-ignition. Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental.
2. Corona stain
Corona stain is a light brown or tan discoloration on the outside of the ceramic insulator above the metal shell/hex. Corona stain is created by the high voltage traveling through the plug that attracts the dirt or oil particles surrounding the exposed ceramic insulator between the wire/coil boot and spark plug metal shell. Corona stain is completely normal and should not be mistaken for exhaust gas blow-by or a broken seal inside the spark plug.
3. Gapping fine-wire spark plugs
While most NGK spark plugs are pre-gapped, there are occasions when the gap requires adjustment. Care must be taken to avoid bending or breaking off the fine-wire electrodes. NGK recommends a round wire-style or pin gauge gap tool to measure the gap. If the gap must be adjusted, use a tool that only moves the ground electrode and does not pry between or against the electrodes. NGK also recommends adjusting the gap no more than +/- 0.008” from the factory preset gap.
4. Torque
Torque is crucial in the ability of the plug to dissipate heat and perform properly. Always follow the manufacturer's recommended torque specification. An under-torqued spark plug can lead to excessive vibration and improper heat dissipation, causing spark plug and/or engine damage. Over-torquing may cause any of the following: thread damage/breakage, compromised internal seals leading to gas leakage, and metal shell stretch leading to poor heat dissipation and pre-ignition.
5.“Copper spark plugs”
“Copper spark plugs” is a term often used to describe a standard material spark plug. However, this terminology is incorrect, as standard material plugs do not have electrodes made from copper. Copper is soft with a low melting point and cannot be used for electrodes, as they would wear very quickly. A standard material spark plug uses a nickel-alloy that may include a small copper core. The copper core has nothing to do with the electrical performance of the spark plug. A copper core is used to increase heat dissipation and durability by lowering the electrode temperatures. Nearly all NGK spark plugs, including precious metal iridium and platinum plugs, have a copper core to increase the electrode durability. Special nickel alloys, platinum, and iridium electrodes, along with copper cores are all used to enhance durability – durability meaning how long a spark plug will last before it needs to be replaced.
 
NGK has dropped ALOT of plugs, and all their plug boots. There have been some counterfeit NGK plugs floating around, not sure if they have that mess cornered now or not .
Interesting. I didn't know they were getting out of the plug cap business. I imagine it's a shrinking market, since most recent engines use COP ignition.

It seems that counterfeits are a growing problem with high-volume well-recognized brand names. It's also a big issue in the cycling community with counterfeit Shimano chains and other parts, and they've gotten so good at duplicating the packaging that unless you have a known authentic one to study very carefully, it can be hard to tell the difference. Power tool batteries are another really common one.

My strategy for minimizing my risk of counterfeits is to buy from known trusted sellers who are sourcing their stock directly from the manufacturer or licensed wholesaler network. Anything from third-party sellers on ecommerce platforms (e.g. ebay or amazon) should be treated with caution. Generally, if the price is suspiciously cheap compared to the average of other known good sellers, there's probably a very good reason...
 
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