Pulled plugs, 1 plug extremely rich

[Pat Dietrich]

Ill post picture when I can but #3 is really black. Took throttle bodies off and also around #3 throttle body where it goes into boot on head it is covered with oil as is the vacume line that eventually goes to airbox. Just right there at the #3 spot. Now I checked valves and they are ok. Maybe a hair on the tighter side on IN ( .004) but they are all the same. But what I did notice is that on this particular cylinder, the clamps that hold the boot to Throttle body when squeezed shut with fingers is still really loose. They all have these little spacers inbetween the clamp so tht it cant be squeezed completely together. None of the others are loose like this when I did the same thing so wondering if it was not sealed good what would my symptoms be. It idled fine but my hp is actually down by 6hp from last time I dynoed so I know whatever is going on with #3 is causing a hp loss. It is extremely rich. This is a 1441 with cp 13.25cr pistons with headwork and 385 megacycles tuned by Ryan Schnitz.Any ideas would be appreciated as always. I need all my cylinders for some 8.60slease:

 

[Pat Dietrich]

Oh also when squeezed with fingers the throttle bodies were not installed. So im not sure how much the bodies expand the boots when installed. I took the spacers out by the way. Need those good and tight with no chance of leaks.

 

[Professor]

Leakdown might be the next step to explain it.

 

[Pat Dietrich]

Same thought. I did do a compression check and all is ok there but i'd better do a leakdown also.

 

[Pat Dietrich]

Leak down was fine. So maybe something with pcv or maybe the injector is sticking??

 

[Pat Dietrich]

 

[IG.]

I would try following the oil. Why was it around #3 boot? If the oil got into #3 throttle body it could gum up on the walls at the butterfly greatly reducing the opening at idle, thus effectively enriching the mixture. Also, if the oil gets into #3, maybe the black color on the plug you see is from oil and not from the mixture being too rich.

If you had a vacuum leak at #3 TB wouldn't that cause a lean condition?

Try doing TB sync and see if you can confirm this.

Any chance you got too much oil in the engine?

Does the bike even have a PCV? I am not aware. But if you do, just take it out, shake and see if it rattles. Or just replace it anyway.

Any chance you got bad connection at plug #3 and it doesn't fire sometimes? (I guess ECU would've thrown a code). That would make it richer.

Any codes at all?

 

[Kaptain Kanji]

I can't see from your photo what all of the porcelain insulator looks like that sits inside the combustion chamber. I think I see the edge of it and it looks clean. The (oil?) remnant looks like it's resting on the outside of the metal electrode facing the camera. I'm suspecting you have some oil getting in there somehow and not a mixture problem.
I would suggest standing your bike perfectly upright and with the front and rear perfectly level, (NOT on a rear stand only) and check your oil level. If the oil is overfull, this can make this oil residue appear in a combustion chamber. BTW, the thickness (weight) and amount of oil in the crankcase CAN affect
the horsepower of the bike.
Good luck on your problem..!!

 

[Pat Dietrich]

No codes at all. The bike does have a pcv on it. The oil level is kept between full and low checked on both tires as level as pos with my wife sitting on bike so i can get a good look at site glass. Been around this bike and sites since april 2001 when I got my 1st one and seen too many topics about overflowing plus I know the hp loss a bike will show with an overflowed crankcase.Put the bike back together with a new plug and took all spacers out of clamps to make sure they are tight and the bike idles about 100-150 higher. Yes thats confusing but it is what it is. Cables are not the cause. Going to take a ride later and beat on it a little then check plugs again. See whatcomes of it. Also plugged airbox and left crankcase open and took crankcase filter out of box. Thanks for helping

 

[Pat Dietrich]

Oh kaptain- the plug was also black on the inside. Ur catching the only little spot thats white on the outside.