On a whim yesterday I pulled my spark plugs on my '07 DWG with 9000 miles on it. I have Reinhart 2-2 pipes and a S&S teardrop and the dealership download. The bike runs good.

There is a white crusty deposit on the grounding strap and the ceramic is white.

When I bought some new ones the parts counter guy said it could be lean or burning a little oil. Another friend/mechanic/drag racer said it could be the result of the crappy fuel we have now days

If it's lean, I thought the o2 sensors working with the ECU would fine tune the A/F mixture after the download got it close. If that isn't the case, what are the o2 sensors for?

What does that sound like to you?

 

The dealership tuned the bike back to EPA requirements, find an indy that can dyno-tune to get a tad more fuel, sounds like you are burning a bit lean.

 

yea dealer only tunes it to epa standards. i had to buy a tuner to get the bike to show some color on the plugs.

 

Your description definitely describes a too-lean condition. The ECU will indeed takes readings from the O2 sensors and attempt to compensate. However, the sensors are only active in closed-loop mode and are narrow-band devices, so their ability to signal radical changes is limited. The download probably did its job, but only affects open-loop. If you aren't planning any further motor mods, a set of O2-IEDs is an easy and inexpensive solution to fatten up the closed-loop. If you are planning further performance mods, find a reputeable tuner in your area and see what they recommend.

 

Your bike is lean. I don't like lean engines. They run hot. Heat is an engine killer. It isn't the gas. No factory map will be rich enough for me. Go talk to Dunc. See what he recommends. We have a good dealer in this area but it is hard to get them to tune a bike fat.