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Discussion Starter · #1 ·
When I did my clutch back in late June, I installed new spark plugs, among other things.

Bike runs ok with the new Iridium plugs, about same as before, but the looks of the old plugs concerns me a bit. 2005 LT with about 35k on the clock.

The plug in the rear-most cylinder seemed "sootier" than the others. Is this normal or is it an indication of something possibly outside accepted norms?

I know that my fuel economy is pretty bad, two up, interstate, premium fuel, cruise control at about 70-75, tires 42/48, 100F temps, and best I can get is 39mpg as indicated on the BC. One up I can eke out about 42 on a good day.

Would photos of the plugs possibly be of any assistance in identifying potential culprits?
 

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Tony if it is dry black looks like you have a problem injector, personally I would try one of the more expensive injector cleaners full bottle per full tank for a couple of tanks of fuel but if it remains dark you can get your injectors cleaned and flow tested
 

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Discussion Starter · #3 ·
I had run SeaFoam through it every tank for about 1500 miles prior to installing new plugs.

I will pull the plugs from the box when I get home and look to see if oily or sooty.

I have a spare fuel rail with injectors that I know works well, so have parts on hand if I need to swap out an injector or four. The friend I loaned it to may even have had it cleaned.
 

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That # 4 plug wire seems to be harder than the rest to get pushed all the way on and also seems to have the sharpest bends in it. I don't know of a way to test it, but it could be part of the problem.

Mine was like that.....dark #4 plug and when I had the plug wires replaced it went away.

Ron
 

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Discussion Starter · #5 ·
I guess that adds one more thing to replace on my bike. Thanks Ron!

Robert, are you keping tally? :histerica
 

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deputy5211 said:
I guess that adds one more thing to replace on my bike. Thanks Ron!

Robert, are you keping tally? :histerica

One would think that you have had quite enough trouble for this year. Time to ride. Come on down to Schulenburg and I'll buy you a beer or three and cook you breakfast Saturday and Sunday. (Houston BMW Club Rally)

Robert
 

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Discussion Starter · #7 ·
Scouter-50 said:
One would think that you have had quite enough trouble for this year. Time to ride. Come on down to Schulenburg and I'll buy you a beer or three and cook you breakfast Saturday and Sunday. (Houston BMW Club Rally)

Robert
No trouble, and been riding lots. Heck, I put two trips to SoCal on that slipping clutch before replacing it! Fuel hose, plug wires, all preventative.

Valve check and adjust... THAT spooks me!

Suzanne and I are discussing the Schulenburg event. Need to check work calendars yet.
 

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plug wires should be 5 ohms, had a bad wire on the K100 - it had a miss at idle - the wires are expensive - up here $70 - $90 each
 
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