Try doing this for a Matchless though and you’re only met with blank stares! If you needed a plug for your Honda motorbike, you just go to the Honda dealer and ask for a plug for your model and they will give you the appropriate one. Also those that were available often seemed to have strange codes that didn’t fit with any of the numbering systems I was used to from back in the UK. The problem was even worse when I was living back in Hyderabad, India as the models of spark plugs available was very limited.
It can therefore be tricky to know what type to install. Spark plugs have changed somewhat in the decades since these old bikes were built and the brands and models listed in the original owners manual may no longer be readily available.
The humble spark plug is obviously quite an essential part of any Matchless engine and is the one component that usually even the most non-mechanically minded will happily fiddle with.
