No Reverse but Shaft turns

[bazas]

Hi, I have a 21' Carvel cabin boat with a Volvo penta MD11C and a MSB gearbox and the reverse has no power. Forward gear works fine with no problems but when I put the boat in reverse the prop shaft turns but the boat goes no where, If I increase the power to the prop then the shaft turns faster as it should but still the boat goes no where. The boat has had a new prop put on in August.

I am at a loss as to the cause. I hope someone has advice.

Thanks Baz

 

[alldodge]

Re: No Reverse but Shaft turns

Hi, I have a 21' Carvel cabin boat with a Volvo penta MD11C and a MSB gearbox and the reverse has no power. Forward gear works fine with no problems but when I put the boat in reverse the prop shaft turns but the boat goes no where, If I increase the power to the prop then the shaft turns faster as it should but still the boat goes no where. The boat has had a new prop put on in August.

I am at a loss as to the cause. I hope someone has advice.

Thanks Baz

:welcome: to iboats Baz

The boat does fine going forward, but when put in reverse no matter how fast the shaft spins you have nothing. It's not the transmission, it's either the shaft, shaft key way, shaft spline, prop or the prop is moving.

Who installed the prop and who made sure the prop shaft mates correctly with the prop?
Does the prop installed using a key or is it a splined shaft?
Recommend pulling the boat out and check to make sure the prop is still secure on the shaft. The prop could be sliding on the shaft.

 

[bazas]

Re: No Reverse but Shaft turns

:welcome: to iboats Baz

The boat does fine going forward, but when put in reverse no matter how fast the shaft spins you have nothing. It's not the transmission, it's either the shaft, shaft key way, shaft spline, prop or the prop is moving.

Who installed the prop and who made sure the prop shaft mates correctly with the prop?
Does the prop installed using a key or is it a splined shaft?
Recommend pulling the boat out and check to make sure the prop is still secure on the shaft. The prop could be sliding on the shaft.

Hi, thanks its a key way. I fitted the prop when she was out the water in July/August. The boat had reverse when she went back in although it wasn't great. All that secures the prop on is a washer and nut with a split pin.

Baz

 

[alldodge]

Re: No Reverse but Shaft turns

Hi, thanks its a key way. I fitted the prop when she was out the water in July/August. The boat had reverse when she went back in although it wasn't great. All that secures the prop on is a washer and nut with a split pin.

Baz

It has to be in the prop area and I'm thinking you have a worn or incorrect key. If you cannot pull it back out see if you can get a scuba diver to have a look.

 

[bazas]

Re: No Reverse but Shaft turns

It has to be in the prop area and I'm thinking you have a worn or incorrect key. If you cannot pull it back out see if you can get a scuba diver to have a look.

Thanks I will have to pull the boat out and have a look. I had a feeling it was something to do with the prop but couldn't figure out why it would run fine in forward but nothing in reverse.

Thanks Baz

 

[alldodge]

Re: No Reverse but Shaft turns

Thanks I will have to pull the boat out and have a look. I had a feeling it was something to do with the prop but couldn't figure out why it would run fine in forward but nothing in reverse.

Thanks Baz

If you said it did it ever since you put the prop on then it could be the prop. But since it started sometime after the prop and was working OK, then something broke or came loose.

Good luck and let us know what you find. Happy holidays

 

[bazas]

Re: No Reverse but Shaft turns

If you said it did it ever since you put the prop on then it could be the prop. But since it started sometime after the prop and was working OK, then something broke or came loose.

Good luck and let us know what you find. Happy holidays

Ok thanks I will have to check in the new year. Too cold at the moment lol.

Thanks Baz

Happy Holidays