Engine runs but prop won't spin

[janofskyj]

Hi,<br /><br />I have a 1988, 88HP Johnson outboard on a 17ft Sunbird. A couple of weekends ago, I was 10 miles out in Cape Cod Bay. From a stop, I pushed the throttle to full speed. Before the boat began to plane, something happened in the drive unit that caused the propeller to stop spinning. <br /><br />I am pretty good mechanically, but don't know much about the drive unit. Can someone tell me what is the likely cause of my problem?<br /><br />Jerry J

 

[Captain Jeff]

Re: Engine runs but prop won't spin

You may have spun the prop hub -basically the rubber sleeve that absorbs shock between the propeller and shaft. Remove the prop and make a mark lining up the inner and outter hub. Go out on the water and get up to the speed at which the problem occurs. Check to see if the marks are still in alignment.

 

[janofskyj]

Re: Engine runs but prop won't spin

Thanks for that info, however, I am sure it isn't the prop. The boat won't move at all now. I had to get towed in. Out of the water, if I put the engine in gear, I can still turn the propeller by hand.

 

[CATransplant]

Re: Engine runs but prop won't spin

Could be a couple of things. The driveshaft on the outboard could have sheared off, or the shift fork may have come disconnected from the shift rod, or the shift rod may have come disconnected at the shift control or at the link.<br /><br />When you shift manually out of the water with the engine not running, can you hear the shift taking place in the lower unit? It should make a heavy clicking or clunking sound when you move the lever.<br /><br />If the answer is yes, worry about the driveshaft. If the answer is no, then it could be either the shift fork coming disconnected from the shifter shaft or the shifter shaft being disconnected from the shift control or at the coupler.<br /><br />Try shifting into reverse. Does this lock the prop with the engine off, and can you hear the shift taking place? If yes, then it's probably the coupler on the shift shaft. If no, then it'll probably be at the shifter.<br /><br />There are a couple of other possibilities, but, they're very unlikely.