
NGK recommended spark plug for both 1300 and 1500 models - use with 0.7mm gap for standard ignition systems. Sold as a set of 4.
These plugs have a 90º groove cut in the centre electrode that forces the spark to occur at the periphery of the electrode resulting in
- Less material to obstruct burn- faster flame kernel growth;
- Less heat energy absorbed by electrode mass – reduced quenching effect;
- Enhances the potential gradient - less voltage required to create spark;
- No loss of service life;