Topic: Plug Fouling after Seafoam Treatment

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Put Seafoam (correct amount) into the engine oil on my CB550K to break down the carbon buildup on her.  Having rebuilt and balanced the carbs a month ago, I also put a splash of Seafoam into the tank.  To my surprise, on the last couple of cold starts in the morning, the plug on cylinder 4 has been fouled alas this piston was not firing until I pulled the plug and cleaned the carbon deposits from her....with Seafoam nonetheless.  After R&R on the plug , she sucks/bangs/and blows on all 4's like a champ. 

My assessent is that the plug fouling is related to the breakdown of the crud atop of the pistons.  Just not sure why its affecting cylinder 4 more than the others.  Compression is great and within spec across all four with less than +/-  two percent btw them.  Plugs are not oil soaked, but rather carbon fouled.  Manometer shows that she still has the balance of a tightrope walker.  Drained float bowls and no signs of particulates albeit the fuel is a bit on the cloudy side.  Not sure if this is a result of putting Seafoam in the tank.

Will this issue clear itself out given time, or should I be investigating other potential issues.  Moreover, has anyone else experienced this phenomenon? Here is my plugs after I pulled them last night to include a photo of the cylinder 4 plug that was not firing.

[flybox1]

under what conditions did you pull the plugs?
WOT? Idle?  just normal around town riding?
wont be from the seafoam.  your #4 is rich....but rich where?  idle? 1/4, 1/2, 3/4 throttle?
you need to do a plug chop in each to determine your next tuning steps.

BTW, #1 is rich also...2 and 3 are a little better.


and shouldn't you be running D8EA's

[Duke McDukiedook]

You only want to put seafoam in your oil right before an oil change to help clean up oil crud.
You don't want to keep it in there long term. All you are doing is watering down your oil with naptha.

[flybox1]

You only want to put seafoam in your oil right before an oil change to help clean up oil crud.
You don't want to keep it in there long term. All you are doing is watering down your oil with naptha.

+1
 get your engine hot, and drain that oil out.  let it drip overnight.

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I pulled the plug for photo-op after initial to minute idle warm-up not having driven the bike because 4 wasnt firing.  After cleaning them up, I am yet to take another photo after driving around town with mid to wide open for circa 5 miles where she performed well prior to realizing I have a repetative issue during another cold start the following morning.  I purchased D7EAs based on SOHC Forum input prior to purchase.  What change should I expect with D8EA's (Hotter / Colder) ect.  She's pulling 18cm of mercury across all four on the motion pro manomenter.  Can drop it down a couple centimeters after initial plug chop but prefer rich over lean.  The question then becomes...how rich.

Will do a plug chop soonest and provide additional photos.  I owe the communitity this, but wanted to ensure that I am not setting myself up for a potential catastrophy at 7K. 

FYI.  I did in fact change the oil after running the seafoam in the oil for 55 miles.  She did not have any seafoam in the oil when the fouling began to occur after the oil change.  My appologies for not stating this in my initial post.

Next up....plug chop, post pics

[flybox1]

well, if the above pic is just at idle, turn your AF mix screws leaner about 1/8 turn on all of them, and maybe a hair more on 1&4.  that might just do it.
plug chops at other throttle positions really arent necessary unless you have something other than stock intake,exhaust and jetting.

if your vacuum readings are all the same, then leave it alone and ride. if you were told D7 plugs...cool.

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Thanks FB1 and DFK1.  Will see if leaning it out by reducing the Air Fuel mixture by 1/8th a turn from its current book value position of 1 1/2 turns out will help keep the plugs from loading up.  She does seem to hiccup a little bit within the 4K and 5K range and could prove to be evidence of why I may have fouled the plug.  Yes, she is all stock and clean WRT the intake setup.  Right now I am going to shake off this 105 degree St. Louis heat and hop in the pool with the family and will report back shortly.

[ekpent]

Personelly I do not reuse or clean known fouled, bad plugs.I throw throw in the trash and break out a new soldier for $2.00.  If you are re using that same old plug in the same hole you may be better off putting a brand new one in     At the very least move the 'bad' plug to a good hole and visa versa if you try to save it.

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The plugs only have 55 miles on them.  Alas, they are new.  If I were running ubber lean, I too would replace them at any mileage upon first indication but that's simply not the case here.  Good point though and well a well received principle. 
As you can see from my photos, I have the plugs numbered and have been purposefully rotating them as a visual means to monitor coil output swapping 1/2 with 3/4 given that the coils/wires are original equipment.  No issue with spark or timing for that matter.  I wish that my optical scope camera had a means to capture photos because you wouldn't believe the amount of crap that has already burned off of my piston heads.  I still believe that the residual residue is what has caused the plug to load up but will continue to provide testimony as things progress.

Till then...

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And the answer is......

The float bowl was sticking on carb 4 causing a very rich condition upon startup causing the plug on cylinder 4 to load up and foul out.  Condition worsenend yesterday when to my surprise, I found fuel on the ground.  Inspection of the overflow tubes pointed to carb 4 as the culprit.  I then took the overflow tube off of the float bowl and watched it drip and reaffirmed this discovery.

Tada!

[Really?]

Thar ya go! 

I have heard of plugs needing to be changed after using SeaFoam but that is only when used at a 100% concentration.