Reverse problem on a 21EC

[PeteLam]

Has anyone had any type of reverse issue? I put my boat into reverse and it does not move at all. The shaft turns but she does not move. I have no problem with forward speed at all......Peter

 

[SlackwaterJack]

If the shaft is turning, unless the prop has come loose or fallen off you must get some motion or propwash....are you trying to back into a strong current? Rudder at 90 deg? :? tied to the dock?

You got me stumped.

 

[PeteLam]

I thought at first it was the current when I was out in the bay,but when I went to dock it would not move in reverse. I made sure the rudder was straight by counting the turns on the wheel. And the shaft turns when put in reverse......Peter

 

[BlueDragonfly]

Have you checked the blade physically. The prop is generally designed to work better fwd than in reverse, if your prop is only slightly fouled with seaweed, it may not show in fwd but really make a difference in reverse.

 

[BlueDragonfly]

By the way Peter, if you didn't realise, because of the directional design of the blades you will need more revs to get a reaction from the boat. Opposing wind direction increases that requirement again, especially where you are in close quarters, you'll have to play with quick spurts to get a reaction at times and your rudder will do very little to help. Bow thruster is the cats meow for steering while moving in reverse.

 

[abcandjrc]

I have seen this happen when the "key" on the shaft-to-prop connection is missing. Contributing factor is that the prop nut loosens a bit. With forward pressure, the prop will push against the taper and have enough contact to move the boat. In reverse, it is pulled off the taper at the first motion and the shaft spins without turning the prop. You may find that under some conditions you don't have full forward thrust because the shaft may not lock onto the prop with full load and it will spin and eventually gall the prop or the shaft. I'd pull the boat and find out what is wrong.

It can take a long time for the problem to occur. The boat I saw have the problem had traveled about 250 miles, including several locks, with no problems. The owner was an accomplished boat handler and was backing it into a covered slip, with a hurricane on the way already producing high winds. He had to use high throttle on the starboard engine to pivot properly. Made a mess of it and couldn't figure out why. I happened to be guiding him in and noticed that nothing was happening on the starboard side. I asked him why he hadn't put the transmission in gear on that side and he said he had. Uh oh.....

We later dove on the prop and it free-wheeled on the shaft. The marina had installed the prop with a tight shaft-nut but no key. The nut loosened enough with the travel to allow the prop to slide off the taper in reverse.

 

[PeteLam]

Thank you all for the info and insight you have provided. I have a friend who is a diver and he is going to take a look. If he cant see anything I am going to haul the boat out. Thank you again......Peter

 

[wefings]

My money is on the brass key........
Marc

 

[PeteLam]

UPDATE....My Tug has been repaired and it was the keyway. It sheared in half and there was no damage to the prop. or the shaft....Thanks to all......Peter

 

[RProffer]

Thanks for the update. I am glad you got it fixed and it was not a major fix. It is important to keep everyone apprised of the solution so others will know what to do in similar situations.