I replaced my plugs a few months ago when I first picked up my SHO.
IMHO, if this is your first time changing plugs in the SHO, and you follow the excellent advice offered by those who posted before me, then it's going to take you several hours to do the job. For instance, I took off the upper intake in order to get at the plugs (can't figure out how some guys don't have to do that), and I'm glad I did pull it off, because it was filthy. So right there I spent 45 minutes soaking and cleaning out the upper intake as best I could before proceeding with the plug job. No way I was putting it back on dirty like that.
And it being my first time removing the UI, I had to fish around a little bit for all the bolts, and it also took a little time for me to figure out how to disconnect the various coolant hoses and electrical connectors so that I did not break any clips or clamps, etc.
Then I followed everyone's advice around here to clean out the plug wells before pulling out the old plugs so that no debris, oil and/or water sitting in the wells will fall into the cylinders. I used a small shop vac with special attachments that fit very well down into the holes. More time right there.
To remove the plugs, I found a universal swivel 5/8" spark plug socket (3/8" drive) to be absolutely essential. It was a tip I got off of this web page:
Changing Spark Plugs - SHO Times
Gapping the plugs and putting anti-sieze on the threads, as well as CAREFULLY installing them and then torquing them to specs (like rangerj and others described) takes some time, as well. Remember, these are aluminum heads, so you don't want to force anything, and you should make sure they are cool when you work on them.
When I did my plugs, I also changed the wires. I recommend that you consider doing this if your wires have a lot of miles on them, since you will have to remove the intake to do the wires, in any case. If the existing wires are crappy, then new plugs alone won't do much to help your Yamaha run better.
I've changed plugs in quite a few vehicles over the years, and the SHO plug job rates up there as one of the more time consuming, relatively speaking.
Good luck, hope this helps. thumb
<small>[ October 31, 2003, 09:06 PM: Message edited by: Rockledge ]</small>