vibration and new plugs

My bike has 12k miles on it. Recently, I changed from running super to mid grade and I started to feel heavy vibration in the handlebars. I read on the board about changing the plugs and performing a TBS.

I changed the plugs with the iridiumand I adjusted the TB, which were only slightly off. The bike now doesn't vibrate as much (still a little, but 90% better)

Here's the question:

Plugs 1, 2 and 4 looked fine.

Plug 3 looked black sooty, though it wasn't really out of alignment.

Is this an issue? How can I remedy it if it is?

Thanks,

ESP

(Other factors that I don't think are mitigating but worth mentioning are that I recently had an accident. This didn't change how the bike runs, other than that the fan isn't turning on and it's starting to overheat.)

Well the only thing that comes to my mind is that the #3 cylinder is the base cylinder for the TBS. So I wouldn't want that one to be too off (lean/rich).

WW

There is a good possibility that with just one plug looking black and sooty that there was a plug wire issue with that cylinder, causing misfire with the resulting vibration. It may have been the plug wire popped off the plug or the plug wire was not making good electrical connection within the rubber plug cap. If the plug were oily black I would have suggested a compression test.

Rad?

There is a good possibility that with just one plug looking black and sooty that there was a plug wire issue with that cylinder, causing misfire with the resulting vibration.

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Yup...that's where I'd look, too.

The plugs were clean, not oily. I'll try to take a picture of them.

Just in case... so you don't think that it had anything to do with running mid-grade gas instead of premium? I understand that these bikes are ok with regular, I just didn't know that when I bought it and I have been using premium except the time when I tried mid-grade because the station was out of 91.

As of changing the plugs last night, the bike felt good. less vibration etc. Should I change the wires as well then?

I'll check the TB this weekend again just to make sure.

ESPrider said:

Just in case... so you don't think that it had anything to do with running mid-grade gas instead of premium? I understand that these bikes are ok with regular, I just didn't know that when I bought it and I have been using premium except the time when I tried mid-grade because the station was out of 91.

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Grade's not going to be an issue...and likely not an issue of bad gasoline as it would manifest itself across the cylinders. You seem to have some issue with this one cylinder in particular. You sure the plug wire is not suspect?

The accident concerns me. If you're not getting an overheat fan....I would suspect an electrical issue over a gas or air issue. In my experience electrics account for 90% of issues with vehicles.

I had the vibration before the accident. Now that I changed the plugs, albeit last night, I don't seem to have the vibration. I didn't notice a power loss or major degradation in fuel economy. I've been getting mid to high 30's in the city and 40 on the highway.

Ignacio said:

ESPrider said:

Just in case... so you don't think that it had anything to do with running mid-grade gas instead of premium? I understand that these bikes are ok with regular, I just didn't know that when I bought it and I have been using premium except the time when I tried mid-grade because the station was out of 91.

Click to expand...

Grade's not going to be an issue...and likely not an issue of bad gasoline as it would manifest itself across the cylinders. You seem to have some issue with this one cylinder in particular. You sure the plug wire is not suspect?

The accident concerns me. If you're not getting an overheat fan....I would suspect an electrical issue over a gas or air issue. In my experience electrics account for 90% of issues with vehicles.

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ESP,

You did not possibly lose the rubber vacuum cap?

One other thing I found in the unusual category, is dirty/corroded Main Wiring harness connector:

https://www.fjrforum.com/forum//index.php?s...mp;hl=connector

I'm guessing a plug lead problem.

I had a vibration/miss that one of Radman's threads put me on to the fix. This is what I did:

'click'

I'm getting a lot of vibration in my handlebars and the #3 plug fouling.

A friend said it coulod be the ignition point and suggested test/changing the wire+point.

I looked on metricparts and saw a plug cap assy. Is this what he was referring to? Do I need anything else to do this?

Your help is appreciated.

ESPrider said:

I'm getting a lot of vibration in my handlebars and the #3 plug fouling. A friend said it coulod be the ignition point and suggested test/changing the wire+point.

I looked on metricparts and saw a plug cap assy. Is this what he was referring to? Do I need anything else to do this?

Your help is appreciated.

Click to expand...

No points ignition system in many years. Electronic ignition is the rule these days on everything, even lawn mowers.. You do have plug wires, plug caps (on the end of the wires) and plugs.

Fred W said:

No points ignition system in many years. Electronic ignition is the rule these days on everything, even lawn mowers.. You do have plug wires, plug caps (on the end of the wires) and plugs.

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I changed the plugs, but it didn't help. What's next? The wire or is there more to it than that? What parts do I need to order?

Thanks

my money is on the throttle body's being out of sync, if your bike has lots of miles on it i would inspect/ check that next.

place to help with that Here

Paging ionbeam or radman....................

There have been the occasional electrical problems with FJRs. I am NOT the expert here, but I would suspect a bad coil?

there is also i sticky noted here on ignition related issues i also check that out as well

motor mount bolts need torqued down?

Mine had handlebar vibrations and when I torqued the bolts it fixed it - try that first..

FJRMGM said:

motor mount bolts need torqued down?
Mine had handlebar vibrations and when I torqued the bolts it fixed it - try that first..

Click to expand...

I'll try that as well. I was concerned about the plug fouling...? I don't know.

Does anyone know a good wrench in the NYC area?

Black sooty plugs indicate a rich cylinder or an improperly firing cylinder.

Try only one of the following at a time! This will help traceability of 'I did this, and this is what happened'.

Given the age of your motorcycle you can't rule out an injector that is not fully closing. You can swap injectors and see if the black plug syndrome follows the injector. Less telling but not harmful is to try some Seafoam or Techron and see if it frees up/cleans a sticky injector.

You say you have Iridium plugs and also mentioned "Plug 3 looked black sooty, though it wasn't really out of alignment". The center electrode of Iridium plugs is very delicate and it is not recommended to either check or gap the plugs. If you have done this you may have damaged the plug. Try swapping the plug with #4 and see if the black plug syndrome follows the plug.

Cyls #2 & #3 share the same coil; if the coil were defective the problem would effect both cylinders. If you have an ohm meter, unplug caps #2 & #3; stick the probes up into the caps and read roughly 32k ohms to 40k ohms. If you can read this value range the plug caps, wires and coil are most likely fine. There is an outside chance that a plug wire may be chaffed and shorting out at high voltages. Try the simple things first, the plug wires are part of the coil and you will have to change the coil to get new plug wires.

Pull out the air filter and confirm that there are no mouse nests, wasp nests or equivalent inside the #3 induction tube restricting air flow, this would also cause a rich cylinder. Could your little incident have dislodged something that got sucked down the #3 intake tube?

Well, these are a few guesses to run with. Good luck!

The plug wires screw into the cap that connects to the plug-often pulling on the wire pulls the wire from the cap and creates a large gap the spark has to jump to fire the plug-like having a 50k resistor inline. The plug will fire at idle and under very light load-but as soon as chamber pressures climb, a mis-fire occurs, the plug gets cold, self cleaning stops, and the plugs take on the appearance you describe. Unscrew the cap from wire, snip 1/2 inch from the wire, and screw the cap in tight. Check the others as well for tightness. Whever I change plugs now I check each wire for a good fit, and find they almost always take another 1/2 turn.