Hi Guys,

I need to machine out 2 factory 155mm Yamaha pump housings to suit the "WSM 003-520" plastic wear rings. I have the wear rings already, but the freight costs of getting replacement pump housings sent to NZ means I need to get the factory housings machined out at the local motor engineering shop.

Does anyone know the diameter/tolerances/clearances needed for the pump housing to suit these wear rings?