Read my plugs
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
I see a pretty normal plug for a Harley, EFI bikes run more grey than brown. Yours are very similar to my Shovel plugs in regards to colour, maybe a bit rich low down but unless that was a WOT plug chop you will always get that rich looking ring.
Cruiser
Joined: Jan 2023
Posts: 190
Likes: 409
From: Scotland UK
I was always told your plugs should have a slightly black / sooty base ring and a nice even light brown or grey colouring up the strap.
Judging by your rear plug, you could probably do with turning in the idle mixture a 1/4 turn to slightly de-richen the mix at the low end but personally I think they look fine.
Judging by your rear plug, you could probably do with turning in the idle mixture a 1/4 turn to slightly de-richen the mix at the low end but personally I think they look fine.
Grand HDF Member
Joined: Apr 2007
Posts: 3,712
Likes: 3,028
From: Brighton, MI
That dark soot on the base ring cold also be from using the enrichener during warm up. (assuming the plugs are from your 92 FLHS). How many miles on the plugs?
The base ring should be closer to like a semi-gloss or satin black, but yours are just a touch powdery/sooty like a flat black. If you use the enrichener for warm up, then I say your fine.
The base ring should be closer to like a semi-gloss or satin black, but yours are just a touch powdery/sooty like a flat black. If you use the enrichener for warm up, then I say your fine.
I have been using the enrichener for worm up until recently. Yesterday I started using the enrichener just the get her started. Then I lock the throttle with the mechanical cruise control at about 1200 rpm. I'm ordering a new set of plugs because these do have quite a few miles on them.
Tourer
Joined: Feb 2019
Posts: 409
Likes: 103
From: Roanoke, VA
I just took out some plugs very like this....worn but still sparking....so me also thinks....pretty good....
Trending Topics
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,004
Likes: 7,539
From: Poolville
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
The Best and Worst Harley-Davidson Moves of 2025
Verdad Gallardo
Nope, no additives. I pulled the plugs to see if I am running rich. I've been thinking I should be getting better that 40mpg. I think I was letting it warm up for too long with the enrichener. Just started doing it different now. I heard someone else say they only used the enrichener for start up. So that's what I'm doing now, getting her started and then using my throttle lock (cruise control) to hold her at 1000/1100 rpm until she's warm.
Seasoned HDF Member
Joined: Mar 2021
Posts: 17,881
Likes: 3,545
From: backwoods
I usually turn the idle up on the carb, Don't really see a reason why not to.