Champion 821 spark plug for the 1998-1999 KTM 50 Mini Adventure and other vehicles fires the spark that ignites the air-fuel mixture in the engine.
- Champion Copper Plus Small Engine line, with a copper core center electrode that allows accurate control of heat range for longer life
- Coated shell that 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
A worn plug can show up as hard starting, misfiring or rough running. Hard starting alone does not prove the plug is at fault, since a clogged fuel filter can cause it too.
Fits
Built to meet OE fit, form and function, this plug fits the 1998-1999 KTM 50 Mini Adventure, the 1997 Cobra King and the 1978 Ski-Doo Citation 300. It is also listed for a wide range of Kawasaki, Ski-Doo and BMW models. If your machine is not named here, find it by make, model and year in the "Vehicles it fits" section.
Specifications
Fit and size
- Plug type: L77JC4
- Thread diameter: 14 mm (0.551 in)
- Pre-gap: 0.030 in (0.76 mm)
- Seat type: Flat
- Washer: Crush washer, included
Build and materials
- Product line: Champion Copper Plus Small Engine
- Grade: Standard replacement
- Center electrode tip material: Copper
- Shell: Coated
- Condition: New
- Country of origin: China
In the box
One spark plug with its crush washer. This listing is a single plug; how many your machine takes depends on the application.
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
Product information is for general reference and may contain errors. See our Disclaimer.
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 the Champion 821 spark plug right for the 1998-1999 KTM 50 Mini Adventure?
Yes. Champion 821 is listed for the 1998-1999 KTM 50 Mini Adventure, and that application takes one plug.
Will the Champion 821 work as a King plug for the 1997 Cobra King?
Yes. This Champion 821 plug is listed for the 1997 Cobra King, which takes one plug.
What thread size and pre-gap does this spark plug have?
The thread diameter is 14 mm (0.551 in), with a flat seat and a crush washer. The plug comes pre-gapped at 0.030 in (0.76 mm).
Does this spark plug come with a washer?
Yes. The listing is one plug with its crush washer included. How many plugs your machine needs depends on the application.
Does the Champion 821 replace a W4AC plug?
Yes. W4AC is one of the numbers on the Interchange line for Champion 821, along with many other cross-references.
