Hell Hath No Fury Like a FJR Scorned!

[MrZappo]

If the plugs were not igniting the fuel well, I would think that un-burned fuel could have been blowing into the exhaust system and perhaps burning in there ? Not sure about this but those plugs look terrible.

Just trying to think this through over here ... Others with more knowledge might chime in ...

 

[TomInPA]

So Seafoam or Iridium plugs? I always got good results without either one.

 

[Ignacio]

It took longer but finally got the temp up to 6 bars and noticed that the red pipes were gone.

That's great! And thinking about it it now at least makes sense to me. The theory being that a plug wasn't firing at all and the unburned mixture was igniting in the cat and combustion was occurring downstream of it.

 

[nsmiller]

Its possible one or more of your plugs is internally damaged. Perhaps torqued too tight or poorly manufactured. As a result spark is was not getting to the cylinder.

 

[RossKean]

That header posted back at #51 is still for sale on ebay. If it was my bike, I think I would replace the header for the sake of $135 and some piece of mind - I still think that you cooked the catalytic converter. I would probably keep my eye out for a (cheap) replacement set of OEM cans too, if only for cosmetic reasons.

I always used to use the iridium plugs. They are hard to get around here so the last couple of sets have been the standard CR8E. Absolutely no performance difference and I tend to run them until valve check is due anyway.

 

[tesla]

Could you please post a picture of the plugs looking at the business end (electrode) side of them? I'd like to see the center and the electrode. Also, can you determine which of the plugs correlates to the cylinder that was getting red? Examine that plug closely - do you see any cracks in the ceramic (either outside or inside)?

Left side pipe was the red hot side (a little red on the right side later on). I assume that corresponds to plugs 1 and/or 2. I examined all plugs and didn't see any cracks inside or out.

Also, perhaps there was some left over "seafoam rich" fuel in the fuel lines and fuel rail. How long did you run the bike after you changed gas and before you removed the plugs?

Ran the bike for about 6 minutes. I'm sure there was still some Seafoam gas left but it was burning at an accelerated rate due to poor running. Two days later I changed the plugs. I see where you're going. Are you thinking that when I fired it up after the plugs were changed I had clean untreated gas? Changing the plugs was coincidental?

Texas doesn't have emission testing on motorcycles. Matter of fact after I got it running properly I got it inspected......only 7 bucks!

I've seen the red "mid" pipes on both sides of my '07. I was afraid they were going to melt something, but she runs fine now and no damage done

Klubis, what were the circumstances that led to your red pipes? Interesting that we both have an 07 but a Gen 2 is a Gen 2.

 

[Klubis]

Daddy always said try the simple things first. Glad the plug changeout worked as well for you as it did for me. Because not all cylinders were firing, unburned fuel/air mixture went down to the cat which did its job and ignited the charge. Fuel combustion that was supposed to happen in the cylinder was taking place in the cat, causing cherry red exhaust pipes. The real mystery is why irridium plugs would act up after just a few K miles and after sitting for such a (relatively) short time. I suspect the massive overdose of sea foam, because that was the common theme in both your and my case. But let's ride more and worry less.

 

[Klubis]

Tesla, 2 or 3 years ago I picked up a used '07 with less than 1,700 miles. It ran like it had been sitting for a while, which it had. I had stalling issues when launching. I read in this forum to raise the idle, which the bike didn't seem to respond to. I hit her with massive sea foam and what was before just a nuisance was replaced with a very unsatisfactory POS feeling. I pulled off the throttle bodies, the fuel rail, and the injectors, cleaned everything, put it back together, drained the tank and the fuel line, put in fresh fuel, put her back together and fired her up and she was absolutely no better. Scared the shit out of myself when I looked down and saw the branding iron hot pipes aft of the cat. Shut her down immediately and hoped that nothing fried, melted, or coked. Only then did I listen to Daddy and check the simple things first. Pulled the plugs and they did not appear to be fouled. Well I had the new plugs on hand so I installed them anyway. Instantaneously changed the bike into what we all know an FJR is supposed to be.

 

[ionbeam]

Left side pipe was the red hot side (a little red on the right side later on). I assume that corresponds to plugs 1 and/or 2. I examined all plugs and didn't see any cracks inside or out.

...Changing the plugs was coincidental?...

There is little chance that the 1-2 plugs corresponded to the left pipe glowing red. The head pipes all join together in front of the catalytic converters so that the O2 sensor can read the combined exhaust. (The following image is linked from eBay and may go away once the product sells.) There are two spot welds on the exhaust, you can clearly see the one about 2-3 inches to the left of the O2 bung, this is what holds the catalyst ring in place on each exit pipe.

It would be more likely that a plug wire wasn't fully seated, or the plug wire is disconnected in the cap, or the resistor cap had oxidized and fiddling with the plug wires took care of the issue. The only thing that may have affected the plugs would be carbon tracking from the center electrode down the center insulator to the metal shell, shorting out the plugs. Since the Gen I and Gen II FJR uses a wasted spark ignition system, any problem affecting one cylinder may well affect two cylinders (1-3 and 2-4).

Edit to add: One should never try to check or gap iridium plugs, they are delicate and the center electrode can be damaged. Yes, some people have tired this and got away with it, but the plug manufacturer does not recommend checking or gaping. Trust the plug out of the box.

In the end we may never know exactly what went wrong. Glad it's fixed.

 

[wheatonFJR]

Moral of the story...

...do NOT scorn your FJR.

Edit: Glad your FJR is feeling frisky again. Nothing like going out into that garage and firing up that 145HP ICBM and going wherever you want to go, whether around the next curve or to the other side of North America.

 

[hppants]

I wish we could have seen a picture looking directly into the electrode, but from Tesla's recent picture, they all look pretty much the same to me. Certainly not carbon fouled. Tesla - was #1 and/or #2 wet (or wetter than the others) when you pulled them out?

I'll buy the "unburned fuel igniting in the Cat causes the pipes to get red" theory. That seems plausible now that I think about it.

Ionbeam - I think you are on the something. Perhaps one (or even two) of the plug wires wasn't electrically doing its job.

I hate to suggest this, but I'm concerned that the problem is going to resurface if you don't recheck the plug wires and boots. During one of my valve checks on the Gen 1, I pulled the plug boot away from the wire and separated it. I just clipped a fresh 1/8" of wire and screwed it back into the boot. Took some long nosed pliers and gently squeezed the metal part in the boot that actually connects to the plug. Ensure a good tight fit. Also, I used that spark plug grease, which I think is just Di-electric grease. You may want to lift the tank and re-check this, if you haven't already done so.

(Disclaimer!!!! I'm no mechanic - more like a parts changer. There is plenty of evidence on this forum to substantiate that. Anyone want to know what the torque value is for the pumpkin drain plug????)

The afternoon I bought my Nighthawk 700s (first bike after an 18 year break), I go to ride the bike and it spins but won't start. Oh shit - buyer's remorse coming on. 45 minutes later - plastics removed, fuel petcock inspected, carb bowls drained, fuel filter bypassed temporarily, spark plugs removed (no spark), and I'm really started to get pissed. I lift my head from under the tank to stare at the wall and really re-think just what the heck I was thinking buying this used piece of shit. Then something red catches my eye - the run/stop switch and it's flipped to "stop".

To quote Jeff Dunham's side kick Walter....

"Dumbass"

 

[Brodie]

Good post explaining the CAT situation in the exhaust header.

Just so the picture doesn't go away when the when the e-Bay add expires, here it is again...

(The following image is linked from eBay and may go away once the product sells.) There are two spot welds on the exhaust, you can clearly see the one about 2-3 inches to the left of the O2 bung, this is what holds the catalyst ring in place on each exit pipe.

A picture IS worth a thousand words.

Brodie

 

[N4HHE]

If the plugs were not igniting the fuel well, I would think that un-burned fuel could have been blowing into the exhaust system and perhaps burning in there ? Not sure about this but those plugs look terrible.

The insulation looks good but there is a lot of crud on the threads suggesting the plugs are not always running as nice as the insulation suggests.

Unburned fuel in the exhaust headers finally combusting is the definition of exhaust popping (which not not a backfire).

 

[audiowize]

Those plugs look pretty black. I would run the bike for 400-500 miles, then pull one out to check the coloration. If they are coming out black instead of light brown/white-ish brown, then I'd be looking at any performance mods as the likely culprit.

 

[RaYzerman19]

Just gonna throw out there that in the old days when I was younger we used to get plugs on bikes where the resistors would seem to break down. The only plugs that worked reliably in bikes were NGK's or Nippondenso's..... Champions, etc. would not stand up.