October 19, 1964

SUBJECT: TEST WHEEL IDENTIFICATION CHART.

Have you had trouble keeping test wheels in order lately, or have you found yourself spending too much time trying to identify the correct wheel to use when testing an engine? - If so, you should find the enclosed chart helpful.

If not, don't throw it away. It still has quite a bit of valuable information on it.

This chart will provide you with a means of identifying all test wheels currently recommended for Johnson outboards so that each wheel can be labeled for quick selection during future tank testing.

Aside from the identifying dimensions, the chart also provides you with a complete listing of model usage for each wheel, along with the minimum rpm that the engine must turn.

Note that three basic dimensions are given for each wheel: over-all diameter, rim width and prop shaft hole diameter. A view showing the wheel broadside is also used, giving the number of vanes or blades in the wheel.

As you match each wheel in your selection to the dimensions of one on the chart (no two wheels on the chart have identical dimensions) be sure to mark the wheel with the correct service part number. Do this until all are identified. A felt-tipped ink marking cartridge similar to the one shown in Fig. 1 works nicely, but just be sure the ink is water proof.

When the job is finished you might even consider arranging the test wheels on a display board to match the arrangement shown on the chart. Then post the chart above or along side of your wheel board for quick reference.

- over -

Later on, when you are about to begin testing an engine, check the chart to see which wheel is recommended. Note, too, the minimum rpm indicated. Then simply select the matching wheel from your display board and install it on the engine.

RC/ll