Champion 821 spark plug for the 1998-1999 KTM 50 Mini Adventure and other vehicles ignites the fuel-air mixture in the combustion chamber with a spark.
- Champion Copper Plus Small Engine line, plug type L77JC4
- Copper core center electrode for accurate heat range control and longer life
- Coated shell resists corrosion in harsh environments
- Pre-gapped at 0.030 in (0.76 mm) to simplify installation
- Engineered for reliable ignition in all weather conditions
Quick facts
- Part: Champion 821 spark plug
- Fits: 1998-1999 KTM 50 Mini Adventure and other vehicles
- Material: Copper center electrode tip
- Condition: New
Hard starting, misfires, rough running or poor fuel economy can mean a plug is worn or fouled. These signs alone do not prove the plug is at fault, since a dirty air filter can cause some of them too.
Fits
This plug is a direct fit for the 1998-1999 KTM 50 Mini Adventure, the 1997 Cobra King and the 1978 Ski-Doo Citation 300, and it is listed for a wide range of other models. Built to meet OE fit, form and function. If your machine 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)
- Pre-gap: 0.030 in (0.76 mm)
- Seat type: Flat
- Washer: Crush washer, included
- Quantity per vehicle: Varies by vehicle
Build and materials
- Plug type: L77JC4
- Center electrode tip material: Copper
- Grade: Standard replacement
- Condition: New
- Country of origin: China
In the box
A spark plug with a crush washer. How many plugs a machine takes varies by vehicle.
Interchange: M40FFX · M41FF · 2634 · Z37 · W3AC · W4A · W4A1 · W4A2 · W4A5 · W4AC · W4AS · L3G · L4G · L77J · L77J4 · L77JC · L77JC4 · 4065 · W31FS · 33821S · 33896329821 · AE091X · AE901Racing · AV091X4 · 2721 · 3626 · 5810 · B10HS · B8HVX · B9HCS · B9HS · B9HS10 · B9HV · B9HVX
This part cross-references / interchanges with the following part numbers:
M40FFX, M41FF, 2634, Z37, W3AC, W4A, W4A1, W4A2, W4A5, W4AC, W4AS, L3G, L4G, L77J, L77J4, L77JC, L77JC4, 4065, W31FS, 33821S, 33896329821, AE091X, AE901Racing, AV091X4, 2721, 3626, 5810, B10HS, B8HVX, B9HCS, B9HS, B9HS10, B9HV, B9HVX
Frequently Asked Questions
Is this Champion 821 the right King plug for the 1997 Cobra King?
Yes. The Champion 821 spark plug is listed for the 1997 Cobra King, and that machine takes one plug.
What gap does the Champion 821 spark plug come set to?
The Champion 821 comes pre-gapped at 0.030 in (0.76 mm). Its thread diameter is 14 mm (0.551 in) and it has a flat seat.
Does the Champion 821 come with a crush washer?
Yes. A crush washer is included with the Champion 821 spark plug.
How can I tell if a small-engine spark plug is worn or fouled?
Hard starting, misfires or rough running can be signs. With the engine off and cool, a worn electrode, heavy deposits or a cracked insulator on the plug can show wear.
Is the 2634 plug an interchange for the Champion 821?
Yes. 2634 is one of the numbers the Champion 821 replaces. The Interchange line lists the others.
