In early 2006 Verner Motor issued a service bulletin and parts kits to retrofit VM133 engines manufactured prior to 2006 with new cylinder stud nuts, spring washers and torque settings. With the completion of the retrofit, Verner Motor is replacing the service bulletin with a new owner's manual that contains a significantly improved maintenance schedule for VM133MK and VM133S engines. Click here for the .pdf file. The maintenance schedule and torque values supercede all previously issued manuals and bulletins.
Included in the new manual is a requirement for 15W-50 or 20W-50 JASO MA specification for oil used in all Verner engines. JASO is a Japanese specification that not all American made oils will meet. The below lists oils that meet JASO MA and are available in USA.
Semi Synthetic - For Auto 92 Octane and 100LL Fuels
Full Synthetic - For Auto 92 Unleaded Fuel Only