I would like to get some advise from somebody with more knowledge than me on the subject of reading plugs. Is my bike running lean, rich or ok? These photos were taken after 18000 miles. Plug on left is front cylinder. Bike is an 09 FLHT running better than ever. Thank You

 

Hello, I also have a question regarding my plugs. I have an 07 ultra with 17,000 miles. I purchased it used with aftermarket pipes and a stage 1 kit already installed. I just installed the full sac performance true duels kit. The plugs look like they have some white coloring to them, but I am not sure if they are in tolerance or not. I read that to much white could mean they are running to hot and lean. If anyone has some input, i would greatly appreciate it. Thanks in advance.

 

Those are good. No white flaky powder residue. If your lean you will have drivability issues. Most FI bikes dont get that ornge look that most are used to looking for.

 

Just an added note, I would try a new set of plugs and compare the new to old, reason is on old plugs you are not sure if its old stuff on there or new, kinda of like trying to track tread wear on a used tire.....just a thought.

 

Thanks for the responses. I finally got some time to get some new plugs and try them out. I put about 40 miles on them this afternoon. The bike is running great. They seem real close to the others i had in there. They do have some tan'ish coloring to them, but not a bright white. I hope they are ok.

 

Wasting your time for the most part.
Except of the real extremes little total soot covered or plain burn off. Modern day ECM's and fuel additives making looking at the plug nothing much more than practices taking them out

 

These I just took out of my 2002 HD Softail standard FXSTI are they **** or they decent looking and clean em abit then keep as spares

 

Its hard to read plugs in pictures and most of these are bad pictures. You need a magnifying 🔎 so u can look into it to find rich bands or aluminum specs from detonation on the band or top.

There are U tube videos of racers cutting plugs apart to read the ceramic.