1974 Evinrude 6HP Outboard

[Guest]

This motor has given no trouble previously. When running with a boat load it works perfectly except if you advance the throttle past the mark "FAST" about another 1.4 inch the motor will suddenly start to race. Moving the throttle back to "FAST" it goes back to normal. Gears change perfectly and it does not slip out of gear. I pulled the prop. I inserted the shear pin in the prop slot and I found I can turn the bearing with a pair of pliers on the shear pin. Does this indicate that the rubber hub around the bearing is worn and needs replacing? Any ideas would be appreciated. Thanks.

Russ (ve6vk-at-telusplanet.net)

[Dick Seiler]

I think the problem you are describing might be caused by cavitation where air is being sucked into your prop stream and decreasing resistance causing the engine to race. Six horsepower is a lot of engine for a Day Sailer and I can see situations where you would start getting cavitation. I have had several experiences with small boats in differing situations where the engine would race and I would reduce the throttle and the prop would engage the water and all would be fine.