I changed my plugs in my 5th gen, for the first thousandish miles it was smooth as silk.
Then cruising on the interstate it suddenly developed engine vibrations like it was missing but I wasn't down on power.
Today I pulled the plugs to find all 4 looking like they have a fine layer of bright red rust on every part of the plug that reaches into the combustion chamber, the old plugs where not like that.
I'm not losing coolant, oil levels not rising or milky, and no rust in the tank.
I had a car that had plugs that looked similar, but the colour didn't affect its operation. At the time, I put it down to fuel additives. (The ones oil companies use--I wasn't adding anything.) This Autolite chart supports that idea. Maybe try a different gas station and/or fuel grade?
Well that explains the color but the vibrations started before the additive. Plugs have been cleaned and bike is being reassembled for a test ride. I was really hoping to find a wet/ burnt plug for an obvious problem to cause the vibrations
To clarify, did you use an additive? Is this the very first time using it on this bike? Did you use it to potentially help with the vibrations or that is coincidental? (Just curious.)
Have you used the same gas stations over these 1,000 miles that you have been using? I am looking for a hint of a new station, out in the boonies, with a storage tank half full of water or other contaminants.
If it were only one plug I would say run it in the dark and look for a spark jumping around. If the spark did not reach that plug then deposits can build up.
For good measure, have you checked the air filter?
Just remember the old "light tan" good plug colour was fort leaded fuel. With unleaded, its a silver/grey normally, which under the older colour chart would be a lean burn colour.
To clarify, did you use an additive? Is this the very first time using it on this bike? Did you use it to potentially help with the vibrations or that is coincidental? (Just curious.)
Have you used the same gas stations over these 1,000 miles that you have been using? I am looking for a hint of a new station, out in the boonies, with a storage tank half full of water or other contaminants.
If it were only one plug I would say run it in the dark and look for a spark jumping around. If the spark did not reach that plug then deposits can build up.
For good measure, have you checked the air filter?
Yes I used the NOS octane boost and only because it was free (damaged bottle they where going to hazmat at work)once and never again. Figured what the hell it cant hurt, nitromethane is a good solvent so at least it will clean the injectors if thats the problem.
As for stations when im traveling I'll use any name brand I happen to be by when Im low. At home it the shell station. I haven't had to use mystery gas in a long time.
Im bad at wrapping up loose ends but after cleaning the plugs and reinstalling them the bike runs great. I can only assume that a plug or HT wire loosened causing it to run roughly. (embarrassing) I dont think the NOS did anything except paint them orange.
Even though an 90º V4 sports perfect primary and second balances they
still vibrate to some degree and the one thing to eliminate if you
feel more vibrations or hear an odd rattle is a loose exhaust system
because it will amplify any of those vibrations to an annoying
level... tap the pipes with the palm of your hand to test if any bolts
points or connections are loose... also check the foot pegs bolts and
anything bolted to the foot pegs...
Yes I used the NOS octane boost and only because it was free (damaged bottle they where going to hazmat at work)once and never again.
You reached the right conclusion about fuel additives... they aren't recommended by
Honda because they failed to be cost effective... the by product is more combustion particles...
Most engines sport 10. to 1 to 11.5 to 1 compression and will still burn 87 happily...
you may hear your combustion chamber ping once or twice each year...
that's not enough to go up one octane... especially if the ping happens on
the side of a steep hill in San Francisco while you're incinerating the clutch
to get moving from a stop light...
Hey Larry I'm disappointed, that looks like an old leaded fuel era chart. The TAN colour is NO longer applicable so what shows best as in #14 is what it used to be with leaded fuel. Since unleaded was introduced, the plugs no longer go tan, that would be an indication of a rich mixture on unleaded. Numbers 20-22 are what a plug should look like on a correct ratio of unleaded fuel.
Agreed. It must be the additive. Since it happened on all four plugs it would be HIGHLY unlikely to be from something else like a gasket issue or coolant leak.
I have also experienced the vibration. But it was on one of my Ducs (the 848).
I changed the oil and it went away. I suspect it was due to overheating the bike during a VERY hot day on an uphill ride in traffic. I think the oil broke down prematurely.
Do the plugs, change the oil and let us know if the vibration went away.
End of thread · 13 posts recoveredWayback Machine snapshot 16 Jul 2017