Regarding Mamod, early thread diameter valves were much shorter in length but this longer type will fit and work perfectly well. If you do have an older engine and prefer the shorter type please just use a tape measure or ruler and check you do not have a 3/8" thread diameter valve. These are to be found on another listing.
Standard Safety Valve Insitu
It is used by all of the models currently being manufactured and a lot that are not now in production. It is always wise to check these dimensions before ordering as older models were made with either a shorter safety valve, more obviously, a fatter one with a 3/8 inch thread diameter.
It will be clear which one you need. The others are on this site also. Email us if you need help on shop@modelenthusiasts.com.
