Champion Spark 686 spark plug for the 2008-2016 KTM 150 SX and other vehicles ignites the air-fuel mixture in the combustion chamber with each spark. It is made for racing engines and delivers rapid, consistent combustion under the mechanical forces of track use.
- Champion Racing Plugs line, plug type C57
- High-strength ceramic insulator that resists dielectric puncture and keeps voltage consistent under extreme ignition loads
- Maintains spark integrity and structural stability during sustained high-RPM, high-heat operation
- Race-tuned heat range; correct heat range selection helps control plug temperature and prevent pre-ignition
- Coated shell for corrosion resistance in harsh environments
- Projected surface-gap design puts the spark deeper in the combustion chamber and manages gap growth over race duration
Quick facts
- Part: Champion Spark 686 spark plug
- Fits: 2008-2016 KTM 150 SX and other vehicles
Hard starting, a misfire or rough running can mean this plug is worn, though the ignition coil or the plug cap may be behind them, so find the cause before replacing anything.
Fits
It is listed for a wide range of KTM, Yamaha, Suzuki and Kawasaki models, including the 2008-2016 KTM 150 SX, the 2010-2014 KTM 150 XC and the 2008 KTM 50 SX Mini. Quantity depends on the vehicle; the 2008-2016 KTM 150 SX takes one. If yours is not named here, look up its year and model in the "Vehicles it fits" section.
Specifications
Fit and size
- Thread diameter: 14 mm (0.551 in)
- Center electrode diameter: 0.052 in
- Pre-gap: 0.025 in (0.65 mm)
- Seat type: flat
- Quantity per vehicle: varies by application
Build and materials
- Plug type: C57
- Center electrode tip material: nickel
- Ground electrode tip design: fine wire J gap
- Washer: crush washer, included
- Resistor: no
- Country of origin: China
In the box
One spark plug with its crush washer.
Interchange: S40XL · S40XLR · 2611 · F09CS · C57 · N1 · N57 · N59G · N84 · N84G · QN1 · 4062 · W31ESU · AG501 · AG501X · B10ES · B9EG · R5671A10 · CR56869
This part cross-references / interchanges with the following part numbers:
S40XL, S40XLR, 2611, F09CS, C57, N1, N57, N59G, N84, N84G, QN1, 4062, W31ESU, AG501, AG501X, B10ES, B9EG, R5671A10, CR56869
Frequently Asked Questions
Does the Champion Spark 686 fit the 2008-2016 KTM 150 SX?
Yes, Champion Spark 686 is listed for the 2008-2016 KTM 150 SX, which takes one plug; for another vehicle, look up its year and model in the "Vehicles it fits" section.
What thread size does the Champion Spark 686 have?
Champion Spark 686 has a thread diameter of 14 mm (0.551 in) and a flat seat.
Does this C57 spark plug come with a washer?
Yes. This spark plug comes with its crush washer.
Is the Champion C57 racing plug pre-gapped?
Yes. This plug comes pre-gapped at 0.025 in (0.65 mm) and has a fine wire J-gap ground electrode.
What does the projected surface-gap design do on this racing spark plug?
It positions the spark deeper in the combustion chamber to improve flame initiation and manage gap growth over race duration.
