I replaced my plugs a couple of weeks ago and wanted to comment on what worked well for me.

We know the battery and battery box have to come out to provide clearance for the back cylinders.

I took off the radiator hose off at the front left of the engine and put it pulled up and away from the engine with a bungee cord tied to the handle bar. This gives you a lot more room to operate on the front left plug. You'll lose some coolant so be prepared with a towel. I had the bike in a stand.....you might lose a bunch more if you are on the kickstand....I don't know.

3 of my 4 coils popped right off and up, with the air blast in the weep hole trick.

I used the plug socket that came with the bike and it worked perfectly. You need to feed the skinny end up above the spark plug opening and then drop the plug end into the spark plug hole opening. Rotating it, it will drop down on the plug and then you need to give it a little push down to seat the rubber plug holder inside the socket.

I then used a 14 MM ratchet box wrench to loosen the plug and if you've got pretty strong fingers you can take the plug out the rest of the way with you hand. There is knurling on the socket to help you grip it and spin it with your fingers. The rubber in the socket holds on the plug and lets you pull it out and it also holds the new plug so that you can feed it in.

I sprayed a little silicone spray on the inside of the coil to allow it to pop back on the plug very easily without having to wrestle with it.

So in short....I would recommend the socket supplied with the bike, Yamaha obviously designed it specifically for this type of application and it works pretty good.

Thanks Mark. I pretty much had the same expeirence when I replaced mine. Good tip regarding the silicone spray. I'll try that next time. What plugs did you go with?

hammer wrote:
NGK's. I got them on Amazon.com for $7.50 each.

This is a great post. I have decided it's not time to change the plugs just by reading the comments here plus the Plugs have only 13000 Miles on them. I shall find another way to enjoy my time with Mrs. Max, may be go for a ride instead.

Mike, replaced my plugs today with the Autolite XS4302's and here is what I found. I'm describing things in detail because of a few concerns that may want to be considered about when/why changing them should be done.

I hope I do this uploading right (from my Dell to my HP) here it goes. The first picture is of the old plugs in the 1,2,3,4 cylinder order from L to R.



They look good
Now here is a comparison one of the old NKG's to a new Autolites.






Notice anything? I measured the electrodes and found that the NKG had lost almost 25% of it's diameter and was now only about 4mm or .018" in diameter after less than 12K miles. Could this ELECTRODE WEAR possibly cause more resistance for the spark to travel through to the tip? Could this also cause a tracking arc condition (through the insulator) or misfire? Also notice the inside ceramic insulator, the Autolite is thicker and does not extend into the cylinder as much.

You guys that bought the new High performance coils a couple of months back via Tim, should be aware that the extra voltage and performance will be nice, but (MAYBE) at a cost of having to replace your plugs more often.

Well see how the new plugs do with my "unknown zone" -- 3/3.5K rpm nothingness condition. As far as the claim that Iridium plugs last much longer, yes they probably could -- but what would they look like and at what cost in performance?

Iridium plugs have a long life & yours show pretty even wear. You could have probably gotten another 12k out of them. Gap woulda been huge & electrode small, but they fire right till the end You got better plugs with Autolite, and piece of mind on plug situation.. On to the rest of smoothing things out!

nicksvmax wrote:
Is it just me, but doesn't it look like the new Autolite is a much colder plug?

If you are talking about the center elctrode on the NGK being smaller, that's exactly the way they are when new.

TnVmax wrote:
Could be, because you are seeing more insulator in that photo.....but I think you need to see down inside more to know for sure.

nicksvmax wrote:
Looks like the new Autolite has more insulator, all at or below the metal body.