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Autolite Finewire Iridium Spark Plug

This product fits a variety of motorcycles. Please select yours so we can find the right part and guarantee fitment. Select A Motorcycle

Product may vary from photo(s).

Everyday Low Price: $8.99

Gold Club Price: What's This? The Gold Club is our premier membership program. For most items members receive 10% off every day, plus exclusive sales and benefits just for members. More Info $8.09

J&P Part: 383-489

Rating: Read Reviews


Autolite Finewire Iridium Spark Plug

• More focused ignition to prevent fouling than leading standard plug

• .6mm finewire design with Sport V-trim ground electrode engineered to offer improved ignitability and durability over standard plug

• Up to 26% quicker starts than leading standard plugs

• More horsepower and better fuel efficiency than standard plug

• Meets or exceeds OEM design

Product Specs

  • Manufacturer Part Number: XS85
  • OEM Reference: J12YC
  • Sold in Units: Each


This product fits a variety of motorcycles. Please select yours so we can find the right part and guarantee fitment. Select A Motorcycle

Harley-Davidson® Models

Duo Glide FLH : 1955–1964
Duo Glide FLHF : 1958–1964
E : 1948–1950
EL : 1948–1952
Electra Glide Fat Bob FLHFB : 1965–1970
Electra Glide FLH : 1965–1973
Electra Glide FLHB : 1965–1970
Electra Glide FLHF : 1965–1974
Electra Glide Police FLP : 1971–1972, 1974
Electra Glide Police FLPF : 1971–1972
ELF : 1952
ELP : 1949
ELS : 1951–1952
EP : 1949
ES : 1948–1950
FL : 1948–1964
FLB : 1965–1970
FLBF : 1970
FLE : 1953–1956
FLEF : 1953–1956
FLF : 1952–1964
FLFB : 1965–1969
FP : 1949
FS : 1948–1950
Hydra Glide FLHF : 1955–1957
Hydra Glide FLS : 1951–1952
Panhead FL : 1948–1950
Super Glide Electric Start FXE : 1974
Super Glide Kick Start FX : 1971–1974
U : 1948
UL : 1948
US : 1948
WL : 1948

Customer Reviews

 gary.clay3 Posted:

I used these to help with a problem my bike has of backfiring once in awhile after the ignition is tuned off. they worked very well and last about twice as long as the original plug

 stumpginny Posted:

Best plugs I have run. evo or tc!

 HeyMnnshot Posted:

Great plug and price.

 brianscottwilson Posted:

so far working well !

 DJBaar Posted:

Great plugs, but make sure you gap them for the ignition you are running.

 gregwenzel Posted:

nice plugs. exact fit! ! !

 jkaran Posted:

Great Value

 crocodiledendy Posted:

Nice plugs. Posted:

Work great hard to believe spark plugs can add pep to a stock bike.

 grnbud Posted:

Great spark plugs

 bmanceaux Posted:

very good spark plugs!

 stevewebb Posted:

Great plugs for the money. Easy start ups on my carb bike. use these on all my bikes

 lanceman72 Posted:

Excellent Plugs!!! Noticed my New Bike (only 2000 miles) runs better after swapping to these. I've put these plugs in other bikes with the same excellent results.

 Reconscout1 Posted:

no problems as of yet, no fitment issues came well packaged and in good condition.

 pedroleo1 Posted:

Still testing on my 883 Iron. So far so good.

 rdhouse1 Posted:

Got many miles out of them, no miss very happy! Posted:

Reliable performance on a mildly modified Twin Cam

 doug570 Posted:

Excellant plugs. Run nothing but Autolite and these are the best.

 pegasus90 Posted:

Great plugs.

 Gator454 Posted:

Smooth running plug!

 Gator454 Posted:

If you are doing your own work it will pay to use these plugs.

 ScribblinJohnny Posted:

Nice plugs, I expect to see a bit better throttle response.

 Wordhasher Posted:

Every time I buy new plugs, I buy the latest, greatest plugs on the market. Then a couple months later, I throw them away and buy another set of these. You think I'd learn, but I'm a sucker for a great ad.

 qqking Posted:

great plug

 aoxender Posted:

Excellent spark plug, smooth idle, excellent performance. Picked with the help of JP Cycles chat line.

 bogasbugger Posted:

Sweet. Slight but noticeable difference. Smoother ride and less popping. It's hard to tell without a dyno run, but the bike feels more tiny bit more powerful. They look really well made, let's see how long they will last. Up to now, they seem like a good bang for the bucks.

 3120684 Posted:

running a 93 hot setup in a 67 flh these are the only plugs i use. they idle better than any other and are excellent on top end. greate for carb motors

 bikenut53 Posted:

these are great, the only plug I found that will go the whole summer on a panhead

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