I figured it's another beautiful day here in Southern California and the last day of 2011 (not to mention 80º) so why not swap out the old spark plugs since the original ones are pushing 25,000 miles. I'm not sure what the recommended replacement figures are and didn't really care since the old ones were working just fine without a single hiccup. 25,000 just feels like a good time to change. A few weeks ago I trolled the web for the best deal I could find on a set of Denso Iridium (Yes, the manual asks for Denso VNH27Z or VNH24Z but that ID has since become IUH27 or 5369) I Tried Amazon, Ebay and various merchants. Ended up getting them at SparkPlugAuto.com for a grand total of $35.81 including shipping and tax. $7.26 per plug. If you're out of CA I imagine you'd save $2.54 in tax. Now, prepping the bike for the big swap. I removed both side fairings to allow me a clearer view of the engine. I imagine you could probably get away without having to remove the plastics, but they're seriously only 5 or 6 bolts per and all of 2 minutes to remove. Once removed, you can clearly see the front 2 plugs. A piece of cake to remove the ignition coils which are each bolted on top of the plugs. The front coils are held down using a 10mm bolt and pull out with very little interference. The plugs are only 2-3 inches deep inside the cylinder head covers. So to get the old plugs out, you're gonna need an actual spark plug socket that has that little piece of rubber inside of it to "grip" onto to plug in order to extract it. VFR's require the 5/8" socket. Now that rubber grip is also gonna bite you in the ass when you're screwing down the new plugs as it's gonna hold onto the plug and not wanna come out the the head cover. I just dropped the new plug in there and removed the rubber gripper from the socket to tighten down. Front plugs, easy. Rear plugs demand you to get the know your bike a little better. Just removing the front 2 bolts on the tank and pivoting it up on it's ass is not enough. Sadly, the sum-bitch needs to be moved even more. So remove the 2 rear bolts as well as the fuel chain stopper chain. That's what the manual calls it. It's actually a metal wire that's held down with the same 10mm bolt. From there you can then pivot the tank off to the side to allow you access to the 2 rear spark plugs. Sorry about the low contrast pics. iPhone cam and did I mention it was sunny as hell? The coils in the rear are held down using the same size allen bolts that's used on the plastics. Now these plugs as crazy deep inside the cylinder heads. I have a 6" extension and it still was not enough. Thankfully I also have a 3" which gave me just enough clearance to get the socket wrench in there. This is where having a proper plug gripping socket comes in handy. But like I said earlier is a PITA when installing the new plug. So just pull out the rubber gripper to tighten. The old plugs were so-so. I use nothing but premium fuel and change the oil every 3000. Then again, they never once failed me. Now being the go-getter I am I figured "how often do I really have the tank off?" So why not give the filter a cleaning and while in there how about I give a carbs a good spraying. So I removed the air cleaner which once opened from the top is very easy to remove with 8 philip screws. 2 holding down each air funnel which leads to each carb. Just pull the air cleaner up to reveal the carbs. I guess you could access each carb without pulling up the air cleaner but I really wanted to spray a whole bunch of carb cleaner in there so I got super ambitious. Cleaned each butterfly, tops and sides of the carbs. Even a nice dousing down each throat. Mmmmmm. Oh yeah, that little white connector at the bottom of the air cleaner (IAT sensor) has to be unplugged in order to lift up the cleaner. Don't forget to reconnect it before you completely tightening the box back down only to get that feeling that you forgot something... I fired her up once the air cleaner was reinstalled just to make sure all was working. Following a good carb cleaning like that I figured it would take an extra second or two to fire up. Which it did. Is there really a difference between the factory plugs and the Denso's? If there is, I really can't tell just yet. But it is nice to know the replacements are engineered to perform just as well if not better than the NGK's I pulled out and not have to go through a plug job for at least another 25,000 miles. Enjoy!
