Johnson Casting No. 310794 - Test Wheel Identification

The number 310794 is cast into the hub of a Johnson 90 HP test wheel, identified by the factory as part number 379695. Owners may also describe this as a test prop or test propeller.

Factory test wheel with arrow pointing to casting number 310794 on the hub — Original factory illustration showing where to find casting number 310794.

Identification from the factory bulletin

Number cast on wheel: 310794
Factory tool part number: 379695
Documented application: Johnson 90 HP V4M(L)-10S and later models, as stated in the October 22, 1963 bulletin
Recommended full-throttle tank-test speed: 4,400-4,800 RPM with this wheel installed

The 1963 bulletin documents this application. It does not establish that the wheel cannot be used on other engines; additional applications have not yet been verified.

Source: Johnson Service Bulletin 990 (October 22, 1963).

For the primary tool reference, see Test Wheel / Test Propeller 379695.