Paragon
Well-Known Member
OK, let me tell you a story! Back in mid April when we had the lovely weather we took the boat out for the day, pottered along the coast, anchored off a beach and later pottered back to the mooring. All fine and dandy!
On the way back to the mooring there was a sort of grinding sound that was worse at higher revs and there seemed to be a reduction in oomph so to keep the noise down we limped back to the mooring almost on tick over.
The problem was identified (on a BW6 gear box) as the output flange was rotating on the shaft, and that is what the noise was. Investigations revealed that the BW7 gearbox was a better box and more or less a straight swap for the BW6 (it's predecessor!). So the hunt then commenced for a replacement BW7 gearbox and the BW6 gearbox was removed from the boat.
Bear in mind this is all being done afloat and to get to everything the fuel tank also had to be removed! Anyway, eventually located a BW7 gearbox and fitted that last week. The output shaft is higher than the BW6 so the mounting brackets had to be lowered to line up correctly. The BW7 is also slightly shorter, so an R&D coupling was used to "fill the gap" and all was going swimmingly.
With everything put back together and checked over it was time to start the engine, turned the keep and the starter engaged but couldn't turn the engine (with or without the de-compression lever moved) and constant trying resulted in smoke from starter motor as it was being overloaded.
After a rest, I eventually got the motor (decompressed) to turn a bit and thought maybe the battery had lost charge after sitting without charge for two months. This evening went out with two battery packs and a complete fully charged battery. Could get the motor turning but it seemed that a lot of effort was required to do it and then only when decompressed, virtually came to a dead stop when compression applied.
In summary, engine was running prior to gearbox removal. It has stood unused with exhaust, fuel and water disconnected for two months. It is not possible to turn the engine by hand and lifting rocker cover off revealed nothing untoward.
ANY help gratefully received, dont know where to start but with all the effort that has gone to getting a new gearbox on it in a confined space and afloat, I am feeling very downhearted at the moment! Can anyone cheer me up?
My grateful thanks in advance.
Engine is c1980, if that makes a difference.
On the way back to the mooring there was a sort of grinding sound that was worse at higher revs and there seemed to be a reduction in oomph so to keep the noise down we limped back to the mooring almost on tick over.
The problem was identified (on a BW6 gear box) as the output flange was rotating on the shaft, and that is what the noise was. Investigations revealed that the BW7 gearbox was a better box and more or less a straight swap for the BW6 (it's predecessor!). So the hunt then commenced for a replacement BW7 gearbox and the BW6 gearbox was removed from the boat.
Bear in mind this is all being done afloat and to get to everything the fuel tank also had to be removed! Anyway, eventually located a BW7 gearbox and fitted that last week. The output shaft is higher than the BW6 so the mounting brackets had to be lowered to line up correctly. The BW7 is also slightly shorter, so an R&D coupling was used to "fill the gap" and all was going swimmingly.
With everything put back together and checked over it was time to start the engine, turned the keep and the starter engaged but couldn't turn the engine (with or without the de-compression lever moved) and constant trying resulted in smoke from starter motor as it was being overloaded.
After a rest, I eventually got the motor (decompressed) to turn a bit and thought maybe the battery had lost charge after sitting without charge for two months. This evening went out with two battery packs and a complete fully charged battery. Could get the motor turning but it seemed that a lot of effort was required to do it and then only when decompressed, virtually came to a dead stop when compression applied.
In summary, engine was running prior to gearbox removal. It has stood unused with exhaust, fuel and water disconnected for two months. It is not possible to turn the engine by hand and lifting rocker cover off revealed nothing untoward.
ANY help gratefully received, dont know where to start but with all the effort that has gone to getting a new gearbox on it in a confined space and afloat, I am feeling very downhearted at the moment! Can anyone cheer me up?
My grateful thanks in advance.
Engine is c1980, if that makes a difference.
