spark plug!

Finally took the time to change the spark plug today as there was a nice break in the cold weather. Plus I was overdue by a few thousand miles... Anyways, I know there are a few of y'all out there who are nervous about working on the bike, and the service manual wasn't helpful at all, so here goes:

Tools:
phillips screwdriver
5mm allen
3/8" ratchet
8mm socket
spark plug socket (5/8" ?) w/ extensions

The spark plug is a little buried:


Start by taking her top off. 8mm for the seat bolts, 5mm and screw driver for the side panels and tank shrouds, 5mm for the tank bolts (careful, they've got a ton of loctite on them esp the forward one).


There's the little goober


Unclip the connector on the coil, then twist and pull to get the coil off the plug and out of the head. Shouldn't take much effort. Make sure you clean the area out first so crap doesn't fall down into the plug well (and later into the cylinder). I used a few shots from a compressed air can to get the dust off and a shop towel for the bigger chunks. There's the plug:


put the stocket on the extensions and slide it over the plug, and remove it. Should come out pretty easy as there isn't much torque on them.

Hmm, yeah it was time to replace it...


Old vs. New.


Make sure to put some anti-seize on the threads of the plug, and then some dielectric grease on the porcelin, put the plug back in the socket, and put it back in the head. Tighten with your hands until it gets snug, put the wrench on and go 1/4-1/2 a turn further and you're done. Torque spec is something like 9.2ft#'s, and over torquing is a great way to ruin your head.

Put everything back together, and enjoy riding around with a fresh healthy motor!

Hey thanks for the great photos. That old plug was sure ugly though. wilburj

skierd, how many miles on that spark plug?

~16,000 miles.

Nicely done

my torque wrenches only go down to 10 ft lbs. you think thats too much? better than guessing i bet.

Yes. First and foremost, your torque wrench is almost certainly not accurate at the bottom of its range and you'll end up over-torquing it. Which means potentially stripping the threads out of the head or worse, which means a new head. Second, the service manual says 9.8" or 1/4-1/2 turn past finger tight. That's served me well in every car I've ever had, never had a plug back out.

Wouldn't change a thing said here all good info & great pix.
Would like to add that an iridium plug indexed will deliver a better spark over a stock plug in backwards.
Will have to do a little shimming but it is worth the little time.
Just be sure you do as skierd said & dress the plug's threads to save the heads threads.

Great post and pics... And by the way I had a good time
getting my coil out the past 2 times I have went to take it out to check the plug. I don't know why it is so hard well as far as hard to pull it out with just my hands(without help with prying it out)
but this last time I put on some anti seece on the coil...so hopfully that will help for next time.)
Any input from you guys?

I wouldn't use anti seize, use dielectric grease instead.

skierd wrote:

I wouldn't use anti seize, use dielectric grease instead.

Yeah i was going to use that....but i ran out. I need to pick some up

This write-up better serves than the MOM! lol

Anyways, mine looks just like yours, but at 11k miles.

why aren't you guy using the much better performace & longer lasting irdium version???
everyone else is for more power & better throttle response.

this is the stock plug correct?
http://www.ngk.com/results_cross.asp?pid=CR9EK&x=37&y=13

thenm this is the ngk iridium version
http://www.ngk.com/results_cross.asp?pid=CR9EIX&x=45&y=11
& this is the denso irdium version
which is the prefered brand of the jdm racers as it's the original design (pattented smaller tip) and is said to perform better than ngk
http://www.amazon.com/Denso-IU27-Iridium-Spark-Plug/dp/B000CJ04B4

If you ever do mess up a spark plug thread try one of these:

http://www.emhart.com/brands/heli-coil

Also, it's a good idea to remove the spark plug from a cold engine.

PonchoV wrote:

Wouldn't change a thing said here all good info & great pix.
Would like to add that an iridium plug indexed will deliver a better spark over a stock plug in backwards.
Will have to do a little shimming but it is worth the little time.
Just be sure you do as skierd said & dress the plug's threads to save the heads threads.

Hey PonchoV,

A little shimming? Can you fill us in on the details? I was hoping the swap to iridium was just plug and play.

Sarah

skierd wrote:

~16,000 miles.

So much for riding the bike at a certain throttle position, killing the motor and then taking a quick plug reading!

zone47 wrote:

skierd wrote:

~16,000 miles.

So much for riding the bike at a certain throttle position, killing the motor and then taking a quick plug reading!

Some will agonize over that.

Most could care less and will just wring it's neck while running its guts out every day...

Why would I want to take a plug reading on a 16,000 mile old plug? Its been a while since I looked, but 1) you need a new plug to tell you anything and 2) at the time I had no way of adjusting the fuel injection settings (and still don't) so there's not much good it would do me anyways. Its not a carb'd bike where jetting needs to be changed. It's not a super sensitive 2stroke either that constantly wants a new plug.

Sarah - I put an iridium plug in the new bike at ~6000 miles, no shimming or any other nonsense. The plugs are the same dimensionally, and I don't bother with trying to index my plug. The theory goes that if you correctly align the spark plug electrodes with the exhaust? port, you'll get a better flame front and therefore more power. There's some science and a decent amount of voodoo that convinces people that fussing with it is worth the extra 1/4hp you might get from it, but I'm not that type.

Thank you! Advance Auto had to order the plug ($7) and I picked it up yesterday. Thanks again.

Sarah

Hmm apparently the plug was broken in my bike, causing the problems. Might want toretun it and get a stock plug...

Hmmm. I got the NGK IX. I'll sit tight and see if we can learn a little more. Glad your bike is coming home.

Sarah

I'm guessing, Skierd, that you just got bitten by the laws of statistical probability. Wouldn't hurt to do a Google search to see if there's other plug failures coming up, however.

Meanwhile... I think I'll add a spare plug to my bike kit. Gotten a little lazy about having a spare plug with me since coming to this thumper from two smoke X'ers.

Apparently spark plugs aren't supposed to wiggle. Looks like the porcelain broke at the base where it attaches inside the metal body.



Bike runs great now, and I also purchased a spare (stock) plug to keep with me. Florida bound in a few days.

Sorry to revive an old thread, but just wanted to say thanks for the guide

I got a new plug in easily thanks to this thread.

I appreciate it!