This spring retains the pressure release ball against its seat, in conjunction with the Pressure Release adjuster, controlling the engiine feed oil pressure on the SOHC engine.
See the full item description against the Pressure Release Adjuster screw, for more information on how this mechanism works, but this spring fits over the pointed shaft of the adjuster screw (Item 0243) and presses the pressure release ball against its seat in the crankcase. Always worth keeping a spare on, as easy to lose them when stripping down to check this mechanism.
These are made to the same conical pattern as the original spring. Price is each.