Spark plugs. When did you change yours?

[yamahaha]

According to the manual my plugs need changing.[div]
[/div][div] I removed them for cleaning and inspection at the required mileage. I feel that was a waste of time because they looked excellent.[/div][div]
[/div][div]I've noticed no change in performance since then.[/div][div]
[/div][div]Is Yamaha trying to get dealers more business? These plugs are pricey and only available from Yamaha (according to the dealer). [/div][div]
[/div][div]Did anyone extend the interval and how did the plugs look?  Thanks.[/div]

[jake]

took mine out at 12,000 and replaced them but they looked fine IMO

[andistyr]

Replaced mine around 15,000 they didn't look too bad.

[Guest Ralph]

Have a look here
 
http://fz07.org/thread/4813/spark-plug-option

[hobbs]

Changed mine when the manual said. Had started to feel like bike was 'off', but I didn't perform some experiment to prove it.
 
Plugs looked like shit when I pulled em, but probably had some life left. I commute more than anything and that's probably tough on a motor with traffic and idling.

[avanti]

In modern car engines with current gas, plugs last indefinitely, despite what dealers sometime try to tell us. I see no reason plugs in modern bikes should be any different.

[AlbatrossCafe]

In modern car engines with current gas, plugs last indefinitely, despite what dealers sometime try to tell us. I see no reason plugs in modern bikes should be any different.

I can see a reason. Modern sportbikes rev between 10k-17k RPM and cruise between 4-8k depending on the engine. That is a lot more firing than your car which will cruise @2-3k RPM. It makes sense that they would wear faster. 
 
That being said, how long did it take you guys to get to your spark plugs to check them? It seems like they are hard to reach on this bike (don't you have to take off the entire tank for plug replacement?). If I was going to check them around the 8k specified interval I think I might as well replace them to save me the labor later.
 

[Beemer]

C'mon peeps, manufacturers can't say how everyone's spark plugs will look like at 8k miles because everyone rides differently, uses different gasoline, has modded their engines and ride in different conditions so they've calculated a safe blanket number (8k) for all riders to abide by so that no one rides with fouled plugs. They aren't saying your plug will only last 8k miles, they're just saying it could be bad at 8k. If your bike is getting good mileage, starts quick and performs well that's a clue you don't need to change your plugs for they're performing like new.

[markstertt]

Plugs on modern 4 stroke engines don't need replacing because they get fouled, if they do, then something is wrong with your engine. Plugs wear out, plain and simple, compare the sharp edge of the center electrode on a new plug to the rounded edge on a 8-10k mile plug, the worn plugs will require a higher voltage to fire which your coils will accommodate up to a certain point. If you want to save a buck, on a std. type massive electrode spark plug, you can pry (carefully & just enough) the ground (side) electrode open so that you can take a flat needle file and dress the top of the center electrode back down to flat with nice crisp edge. Then take a file to the end of the side electrode and dress it back to achieve similar results, regap to specs and you're good to go. Or just get a set of fine wire iridiums and see if you can't double or triple that change by date, NGK LMAR8AI-8 are what I purchased and are used in the BMW 1600cc bikes but try to get them elsewhere as I'm sure BMW will charge a premium. They are around $14 ea. shipped on the internet, I used www.uk-motors.de to purchase a 4 pack for $56.73 US...Mark

[markstertt]

I forgot to mention this, when I received my iridiums, I inspected them closely and could not see any platinum ground pad on the side electrode like NGK advert implied. No big deal, still an iridium fine wire center electrode but heck...Mark
 
 
PS..NGK stocking? number for those laser iridiums is 92288

[avanti]

Well, then... if all is still running okay at 20K I'll checks plugs first thing. ;-)  As to the official manuals, is there a reason why the US and Euro recommended grades of gas are different???  Just curious about some of the things that get into manuals... sometimes more for potential legal reasons than engineering ones?
 

[markstertt]

I seriously doubt Standard NGK plugs will be fine at 20k miles, but if they are please let me, us know as I'm sure Yamaha is being conservative on their recommendation interval. Some people will notice their engines drop off in performance a lot sooner than others, some almost never. It may just be a little harder to start on a cold day, maybe won't idle as well, drop off in mpg...it's just to bad that it's such a time consuming job to change a couple of plugs.

[hobbs]

In modern car engines with current gas, plugs last indefinitely, despite what dealers sometime try to tell us. I see no reason plugs in modern bikes should be any different.

I can see a reason. Modern sportbikes rev between 10k-17k RPM and cruise between 4-8k depending on the engine. That is a lot more firing than your car which will cruise @2-3k RPM. It makes sense that they would wear faster. 
 
That being said, how long did it take you guys to get to your spark plugs to check them? It seems like they are hard to reach on this bike (don't you have to take off the entire tank for plug replacement?). If I was going to check them around the 8k specified interval I think I might as well replace them to save me the labor later.

 
 
2 hours and at that point, just replace them. I'm about to do mine for the 2nd time and I think I can do it in an hour or so. I have a much better workshop now.

[yamahaha]

 

That being said, how long did it take you guys to get to your spark plugs to check them? It seems like they are hard to reach on this bike (don't you have to take off the entire tank for plug replacement?). If I was going to check them around the 8k specified interval I think I might as well replace them to save me the labor later. 
 
 

You don't have to take the tank off but its still not the nicest job.  I won't be pulling plugs out again for cleaning. I will go the full mileage and more and then change them. Thanks for everyone's input.
 
I've got plugs coming. About 16 bucks CAD each from the dealer. Honda cross referenced plugs and theirs were 32 bucks a piece! Yikes.
A little cheaper at Ebay after the smoke clears but not much.
http://www.ebay.ca/sch/i.html?_odkw=spark+plugs+for+fz07&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=ngk+lmar8a-9&_sacat=0
 

[Guest Ralph]

Well, then... if all is still running okay at 20K I'll checks plugs first thing. ;-)  As to the official manuals, is there a reason why the US and Euro recommended grades of gas are different???  Just curious about some of the things that get into manuals... sometimes more for potential legal reasons than engineering ones?

We use RON to measure octane you use MON so the numbers on the pumps are different but there's little difference 
in the fuel,  you also sometimes get differences is the oil change intervals but that seems more to do with how keen
people are to do servicing, you seem much more keen to change oil in the US than we are so long service intervals
 
are a good selling point over here, my car has 17000 mile intervals though even I think that a bit over the top, the 07
 
is at 6000 miles here,  I had a SV Suzuki and that had totally and much more precise  running in instructions for Canadian
bikes. they just do  things to suit the market.
 
 

[wickedtwister]

My standpoint on it is ill pull them and check at or before the interval and if they aren't too expensive (which they are not expensive on the fz I think I got mine for 6 bucks each) I'll just change them. The plugs on the z1000 are 26 bucks each (4) I think on the Ducati 749 they were 35 each.
 
I change the plugs, oil and air filter, oil, and brake fluid every year on both bikes. Is it excessive? Probably but it puts the bikes in the best condition to run all summer long without any down time.

[biggaudi]

All I have to say is be glad you don't have to replace VW diesel glow plugs for $125 a pop which you can only purchase through VW >
 
Bitter much? Ummm yeah.
 

[Guest Ralph]

All I have to say is be glad you don't have to replace VW diesel glow plugs for $125 a pop which you can only purchase through VW  
Bitter much? Ummm yeah.

Likely you would get them much cheaper via the UK or Europe  were Diesels are more common, got a set of 4 for my Renault
for about $70 about the same as Iridium spark Plugs in the UK

[sorkyah]

All I have to say is be glad you don't have to replace VW diesel glow plugs for $125 a pop which you can only purchase through VW  
Bitter much? Ummm yeah.

Just be glad you arent rplacing the injectors themselvez...
 
$8-900 depending on the dealer

[markstertt]

Update on iridium NGK plugs that I said I was going to use in my FZ-07, STOP! don't buy these plugs, I just went to install mine and ran into a major problem. The problem is the small threaded end where the plug cap attaches, some installs use the little cap & some don't, in which case you take the cap off and the threaded end inserts into plug cap, usually no problem except on this iridium ngk the cap does not unscrew, I found out by turning it until the core rod snapped in half.
 
I'm truly sorry if anyone else bought these iridiums on my recommendation, I'm kind of thinking no one has or I would have heard about it by now.
 
I may take a remaining iridium, chuck it up in the lathe and turn the end cap into something I can use since all other parameters were the same as OEM except for the fine wire iridium center electrode.
 
The original plugs at 7800 miles looked pretty good, with the center electrode a little rounded on the back side towards the ground electrode but gap was pretty close to spec. and could have gone to 10,000 miles without worries I would think...Mark

[markstertt]

Final update on the NGk LMAR8AI-8 iridium plugs. Good thing I bought a 4 pak since I ruined one more in the lathe, spark plugs are very fragile and break easily. Being an amateur machinist, it took 2 tries to get it right, a tool post grinder was the answer and reduced the plug end post dia. down to that of the stock plugs (.146") easily, followed up by a very thin cut off wheel to cut grooves in the post to simulate the threads of the original plug. Now the COP snaps onto the spark just like stock, they are installed in the engine and unless for some reason I don't like them, they will probably be there for the next 20k miles or more.
 
Had I not already purchased these plugs I probably wouldn't have gone to the trouble, maybe Denso or some other mfg. will have an easier alternative fine wire in the future, I just really didn't look to hard since I thought I had an easy solution.
 
Oh, a little silicone dielectric grease on the plug caps interior lip and exterior diameter at the top will ensure an easier removal the next time around. I use Dow Corning DC4 and a small tube will last a lifetime it seems.