VFR Discussion Group -> Spark Plug Replacement Time?

I have an 04 (6th Gen) and the manual says to inspect the plugs at 16K MI, but does not say when to replace them . I have 17K MI, and I pulled them all and they LOOK fine, but with these new Iridium tipped plugs I have no idea what I am looking for.

Anyone have any experience with the longevity of these plugs or have any suggestions? At $60.00/box for new plugs I would rather get as much life out of them as I can...

StealthBlack04, Apr 12 2005, 10:00 AMI have an 04 (6th Gen) and the manual says to inspect the plugs at 16K MI, but does not say when to replace them .  I have 17K MI, and I pulled them all and they LOOK fine, but with these new Iridium tipped plugs I have no idea what I am looking for.

Anyone have any experience with the longevity of these plugs or have any suggestions?  At $60.00/box for new plugs I would rather get as much life out of them as I can...

The manual calls for replacement at 32,000.

StealthBlack04, Apr 12 2005, 08:00 AM
LOOK fine, but with these new Iridium tipped plugs I have no idea what I am looking for.

Your checking the electrode for contamination with accumulated deposits and if the end is rounded...

You may clean the deposits off with a professional air driven plug cleaner with pressure less than 85psi for less than 20 seconds... anymore pressure and any more length of time the Irid may be damaged... do not use a wire brush as it may leave deposits that will melt on the electrode...

If the end of the electrode is rounded then it's replacement is recommended...

I just replace them every time I do a valve check/adjustment. You need to pull them anyhow, so just replace them. There is a crush washer that gets compressed on first install, which makes torquing the plugs on a second removal a little more necessary. I have heard horror stories of stripping out plug holes, so long story short, I just change them and rely on the new crush washer to do it's thing. As usual, I'm sure BLS will have a different view, but I'm sticking to my story. :)

one of the first things you learn in reciprocating engine theory is that once a spark plug becomes fouled, it cannot every be cleaned sufficiently to restore normal operation. you can scrub, spray and even use a spark plug media blaster, but it will never transfer current as efficiently as a new plug. you may get it to acceptable levels but the cost of new plugs is worth the expense over 16,000+ miles

sailcycle, Apr 12 2005, 10:07 AMThe manual calls for replacement at 32,000.

Wow, the 5th Gen calls for replacement every 8k miles.

When I brought my bike to the stealer in March to change the fluids, I don't think it's been done since new, they called me mid service to ask me if I wanted to change the plugs, "since the plastic was off".

First, when I told them I wanted the brake fluid, coolant, clutch fluid, and oil changed they tried to sell me some over-priced oil change, which included a wash and to "check over" the bike, you know make sure the lights are all working. For this they wanted an extra ~40 ducketts. :salesman:

So being skeptical and ignorant to when the plugs should be changed, I asked him, well did you pull them and are they dirty?

Oh no, we just figured since we had the plastic off.

Well, the bike only has 3500 miles on it?

Oh well, I think Honda recommends replacing them at the 6k mi service.

6k mi service? right, no thanks. :P

So, I still have the question of experience with 5th Gen plugs and replacement. Does the fact that the bike, a 2000, only had 2500 miles on it when I bought it in Sept 2004 factor into the equation?

Anyone care to rate the difficulty of changing the plugs?

hi


on my 95' VFR , i am still running with the original spark plugs, it counts now 50000Km, and the engine starts in the first touch of the ignition button...always



Jaime Reis

Platinum or Irridium plugs

Change every time you check the valve clearance. (forget the book on this one)

:)