Triton,
As you say, the 2 idler spindles have hex heads - these locate by 2 of the flats into slots milled across the inside of the crankcase. The slots are about 3/16" deep, so if the heads are not properly located in the slots, it would be impossible to fit the nuts and insert the split pins. On the Dragonfly, the timing gears are wider than on the Mark series, resulting in no boss to the outside of the gear. This in turn causes the gear to rub on the strap when there is any wear in the bore of the gear or on the OD of the bronze bearing bush (which should be about 5 thou longer than the gear, so that the gear still rotates when everything is tightened up). To prevent further wear to the strap, you could try inserting thin washers on the 2 studs and the spindle before fitting the strap - but make sure the washer on the spindle is large enough in diameter to provide a bearing surface - preventing any increase in the end float on the idler gear. Make sure the nuts on the spindles are adequately tightened and that the shoulder on the spindle is below the end of the bronze bush, thus ensuring that the nut actually clamps the whole assembly in the crankcases. Loose idler spindles are not unknown on Dragonfly motors.
Regards,
Eddie.
