Dual Platinum Spark Plugs

[ionbeam]

...I'm sure that the stock ones will still last at least 15k miles with no problem. How much longer would you really want to leave them in for?

27k miles? Then change them at valve adjustment time when you are already under the tank with the T bar off.

 

[Fred W]

I'd bet that they would last that long no problem, especially now that they are COP. I'm in the habit of changing mine (non-iridium) at 15k miles and then again 10k miles later at the 25k mile valve checks (I round all of my maintenances to 5k increments).

For many riders that 25k or 27k miles would be a very long time to leave the plugs screwed in there. Still... I bet they'd last that long fine.

 

[RaYzerman19]

Judging by all the FJR plugs I have seen, 30k shouldn't be an issue, especially with COPS.

 

[pista]

<blockquote class='ipsBlockquote'data-author="J-Luv" data-cid="1149742" data-time="1400784717"><p>

Some days I think I'm pretty smart. I learned something here today that was completely foreign to me when I arose. The more I know, the more I know that I don't. I appreciate the earned expertise displayed. Here ends the gratis humility lesson (for the moment).</p></blockquote>^^^ this

 

[Slardy]

Folks,

The dual platinum plug that I use is the NGK CR8EK, where the K means two ground electrodes. See Fred W's post (in this thread) for an explanation of the other letters and number.

Slardy

 

[Twigg]

And it is almost right.

Electrons flow from negative to positive. (Hole flow theory is pretty outdated)
Other than the polarities shown at the coil secondary being reversed, this diagram is otherwise correct.

As for the big three automakers having used wasted spark in the past, that is (sadly) true. My 5.0L V8 Exploder had a wasted spark design. It called for double platinum plugs (both electrodes were platinum) and still the plugs never lasted 100k miles.

Nowadays, Coil Over Plug (COP) is all the rage, and this is what we now have in the 2013+ FJRs. Every plug fires in the normal direction, so iridiums would be beneficial on a 3rd gen FJR.

Ford Motorcraft plugs are specified differently for the front and rear banks of cylinders on the WindStar. From the factory, different plugs are fitted, but the replacements are the same part # for all six.

This is because Ford specified that the plugs that fired the correct way had one electrode plated with platinum, and the ones firing the wrong way had both electrodes plated. The replacements all have both electrodes plated.

My suspicion is that they were saving a few cents per plug, which probably makes sense when you are buying them by the million

An oddity, but it fits with the wasted spark system.

I can confirm that the original plug in cylinder #1 went 110000 miles, and was still firing correctly according to the OBD II data stream. I know it was original because it was the type unavailable as a replacement (and it is very difficult to replace).

 

[Flash1034]

So why does the factory specify 8,000 mile plug change intervals on Gen 3s?

Flash

 

[Fred W]

Mostly because they like to charge people for replacing plugs. Same reason they specify a TBS every 4k miles.

 

[Flash1034]

So why does the factory specify 8,000 mile plug change intervals on Gen 3s?Flash

So what is the forum recommended plug change interval for a 2014?

Flash

 

[Allen_C]

So why does the factory specify 8,000 mile plug change intervals on Gen 3s?

Flash

So what is the forum recommended plug change interval for a 2014?
Flash

When needed. Could be 12-24k miles. I changed mine at 8k but didn't really need to. Checked then at 16k and they looked good so back in they went. I now have 23k and will check them again before I head up to South Dakota.

 

[Ignacio]

So what is the forum recommended plug change interval for a 2014?
Flash

The same as a 2003-2013.

 

[ionbeam]

So why does the factory specify 8,000 mile plug change intervals on Gen 3s?

Flash

So what is the forum recommended plug change interval for a 2014?

Flash

Change them when they need changing

In modern engines with modern ignition systems plugs don't go bad like a light switch, they slowly, very slowly degrade. I'm pretty sure based on engine feel and gas mileage you couldn't tell the difference between new plugs and 50k mile plugs. For the health of the ignition system (coils & wires in Gen I & Gen II engines) you should change plugs at some point but it is completely arbitrary. Every (throwing a dart at the dart board...) 27k miles would work, it's when you are already there for a valve adjustment. If your engine does show a long slow gas mileage decline the plugs may be one of the first things to get changed but I *really* doubt that in 27k miles that would happen without an additional problem like a plugged air filter or carbon buildup from lots of cold starts and short rides.

There is a big difference between recommended and required change intervals. The Gen 3 engine with direct ignition coils should be even easier on plugs as opposed to the older wasted spark system that double fired the plugs (once on ignition and once on exhaust).

Edit: I see Allen_C posted basically the same thing while I was typing.

 

[RichDoyle]

Every bike I've ever seen uses a wasted spark setup. Caveat: I haven't really seen that many bikes...

Singles don't. Triples don't. And Honda SL350K1's don't.

Historically most older 4-stroke bikes with 2 cylinders or more and an even number of cylinders do. But there are a few out there with automotive-style distributors that don't.

 

[DezzertRider]

I just "tried" to replace my plugs and broke one of the plug caps. Just one plug cap cost $51.00 and it will take 2 and half weeks before it arrives. So I have no electron flow from neg to pos or pos to neg. And now I find that I wasted money on iridium plugs.

 

[Allen_C]

I just "tried" to replace my plugs and broke one of the plug caps. Just one plug cap cost $51.00 and it will take 2 and half weeks before it arrives. So I have no electron flow from neg to pos or pos to neg. And now I find that I wasted money on iridium plugs. :fool:

Du'oh! How did you break the cap?

 

[Fred W]

@DezzertRider - If the cap just came separated from the wire, that is no big deal. They are supposed to do that. Just snip 1/4" off the end of the wire and screw the cap back on the wire.

 

[rwortman]

I want to see pictures of 50K mile plugs with every other one worn out. Until then this is a discussion about imagined problems.

 

[bigjohnsd]

Once again we are "Pole Vaulting over Mouse Turds"

 

[DezzertRider]

My bike is 11 years old (2004), so I suspect this was part of the issue. I purchased about 10 months ago (garage queen with 4400 miles). So with these things being in there for 11 years and probably never removed, they were a bear to get out. I was able to get two of them off without any tools but a lot of verbal encouragement. The third one came off with channel locks and additional verbal encouragement. The last one which broke (using channel locks), actually came apart and the top of the spark cap broke off. So this is why I had to order the part ($50.00) for a rubber cap - seriously

.

I will cut off about a 1/4 inch of the spark plug wire on the one that broke and re-insert it once I get the new one. I will also put some form of grease around the top part that fits so snuggly into the spark plug well so that I can avoid this problem in the future. The plugs actually looked fine and probably didn't need replacing. The short interval that yamaha says to replace them IMO is overkill. After breaking the plug cap and walking away for awhile, I came back to her and apologized for all the verbal abuse.

 

[ionbeam]

..I will also put some form of grease around the top part that fits so snuggly into the spark plug well so that I can avoid this problem in the future...

This is actually one place that dielectric grease is intended to be used, just a little in the cap (or lightly on the porcelain part of the plug). Do not get dielectric grease on any electrical connections. A good spritz of silicon spray would do a good job too. How ever tempting the sound of 'anti-seize compound' is, it may not be a good choice because it often contains a small percentage of metals which could cause the spark plug to misfire to the cylinder head.

Just as a side note, the plugs would have to be removed to do a valve adjustment on or about 27k miles. If you suspect the plug caps have never been removed you may want to worry a bit about the valve check. It isn't uncommon for no adjustment during the first check, but then again, some do indeed need adjusting.