Prop rotation

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misty341

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Hello there, just last week I got around to trying out a new prop for my boat, a westerly fulmar, only to discover that the control lever now drives the boat goes forward in reverse and reverse in forward !.
At first none of this made sense but this is what I know so far. The engine is a Beta 28 - right handed of course - and the new prop is a flexofold 2 blader which is also right handed. It seems that back in 2007 the then owner changed the original volvo for a beta but the left handed propellor was not changed and the control cables were simply reversed!.
I'm thinking now that I should reverse these cables and was wondering if anyone has done this before and has any advice about how to go about it.
Thanks
Matthew
 
Assuming the transmission is fully rated in both directions, it should be straightforward. My Twin Disc are.

Look at the linkage at the gearbox - it might be simply a case of taking it off moving it 180 degrees then re-connecting, or as you suggest swap the forward and astern cables.
 
misty341 said:
Hello there, just last week I got around to trying out a new prop for my boat, a westerly fulmar, only to discover that the control lever now drives the boat goes forward in reverse and reverse in forward !.
At first none of this made sense but this is what I know so far. The engine is a Beta 28 - right handed of course - and the new prop is a flexofold 2 blader which is also right handed. It seems that back in 2007 the then owner changed the original volvo for a beta but the left handed propellor was not changed and the control cables were simply reversed!.
I'm thinking now that I should reverse these cables and was wondering if anyone has done this before and has any advice about how to go about it.
Thanks
Matthew
Click to expand...

Just swap the gear cable over on the control head so that it pushes rather than pulls. Don't think that gearbox is rated to run in either direction and the ratios are different. You need the instructions for the control head to decide which hole to use.
 
I don't think it is rated to run in either direction and i'm almost sure the ratios are different. Its a prm 80 gearbox. Tranona, what is this 'hole' you refer too?
 
If the transmission isn't rated in both directions, it would seem that you are doing the correct thing by installing a right hand prop on a right hand rotation engine. As others have said, just reverse the cables on the control head.
 
From fisherman's link
The gearbox is purpose built to operate with standard rotation engines i.e. providing a clockwise rotation of the gearbox input shaft when viewed on input. In forward drive the output shaft rotates opposite to input shaft therefore requiring a right hand propeller.
Click to expand...
So that's clear, isn't it?
 
misty341 said:
I don't think it is rated to run in either direction and i'm almost sure the ratios are different. Its a prm 80 gearbox. Tranona, what is this 'hole' you refer too?
Click to expand...

The cable attaches to a lever in the control head. The are different holes depending on whether you want the cable to push or pull when you move the lever forward. Some gearboxes require a push to engage forward and some a pull so this gives a choice and you need to move your cable to the correct hole. It will become obvious once you get to the back of the control head and is fully explained in the instructions for the control.
 
When I re-engined my boat, I had to replace the prop as the gearbox was not designed to prolonged running in reverse. I was told this was because in reverse, the thrust bearing wasn't engaged. I didn't question this assertion at the time, haven't got drawings of the box and have never had to strip the box so I can't comment on the accuracy of the statement. CoxEngineering (VicS of this parish) is a mine of useful information or contact the engine/gearbox supplier for a definitive answer.
 
Thanks everyone for the replies. This would explain why the boat had such poor drive going forward, it took us 38 hours and a shed load of fuel to take it back to Dublin from Scotland. I hope now that changing the cables over will resolve this and that there isn't any damage done to the gearbox having run the wrong way for 7 years. Low hours though.
I have to say that the main reason for the prop change was that the old one, a volvo 3 bladed folder, was in very bad condition - gear teeth had ground away and the blades were very pink and brittle.
Mind you, for all my observations I never noticed that it was left handed!.
Darglow Engineering who supplied the new one have been excellent.
 
Not only would it have been the wrong hand, but also the wrong size for the new engine. Past owner was a bodger.
 
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