bayliner2452
New member
Heads up, newbie about !
Ok folks, I have just bought an new 5.7 Vortec to replace my worn out 5.0l Mercruiser. My original Alpha engine coupler (18643A5) was looking a bit rusty so I decide to fit a new one (aftermarket) This turned out to be from a bad production batch as the shaft coupling was about 1.75mm out of centre with the mounting plate. fortunately I found the problem whilst testing the new engine out of the boat. The supplier conceded that their had been a problem at the manufacturers and that a number of couplers had to be returned. after a month of waiting for a replacement I gave up and refitted my original coupler. With the engine back in the boat I could not get the coupler to align using the alignment tool. Note that I mounted the coupler on the flywheel in accordance with the recommended procedure i.e using counter sunk screws to ensure it was centred the replace each of the countersunk screws in turn with the proper mounting screws. Using a 1" tube fitted in the coupler and rotating the engine by hand it was clear the my old coupler was bent. Engine out again and I eventually managed to find an original quicksliver coupling at a supplier about 70 miles away. I decided to check the coupling on a spin table with a dial gauge. The mounting plate was true but the actual coupler was running out of true. I could not tell from my crude test setup if the coupler was cast out of centre in the rubber block or just cast out of perpendicular with the mounting plate. Loosing the will to live, I decide to try it out in the boat. You guessed it - struggled to get it to align. I eventually managed to get a smooth low pressure alignment tool insertion so I rotateed the crank 180 degrees by hand and tried again. No chance, the alignment tool bound up immediately and I could not get more than about 5mm of insertion.
Am I just extremely unlucky or has anyone else had recent problems with poor quality engine couplers. Or am I doing something fundamentally wrong.
I am an experienced engineer but I'm relatively new to boat engines.
Any help or insight would be much appreciated.
Wayne
Ok folks, I have just bought an new 5.7 Vortec to replace my worn out 5.0l Mercruiser. My original Alpha engine coupler (18643A5) was looking a bit rusty so I decide to fit a new one (aftermarket) This turned out to be from a bad production batch as the shaft coupling was about 1.75mm out of centre with the mounting plate. fortunately I found the problem whilst testing the new engine out of the boat. The supplier conceded that their had been a problem at the manufacturers and that a number of couplers had to be returned. after a month of waiting for a replacement I gave up and refitted my original coupler. With the engine back in the boat I could not get the coupler to align using the alignment tool. Note that I mounted the coupler on the flywheel in accordance with the recommended procedure i.e using counter sunk screws to ensure it was centred the replace each of the countersunk screws in turn with the proper mounting screws. Using a 1" tube fitted in the coupler and rotating the engine by hand it was clear the my old coupler was bent. Engine out again and I eventually managed to find an original quicksliver coupling at a supplier about 70 miles away. I decided to check the coupling on a spin table with a dial gauge. The mounting plate was true but the actual coupler was running out of true. I could not tell from my crude test setup if the coupler was cast out of centre in the rubber block or just cast out of perpendicular with the mounting plate. Loosing the will to live, I decide to try it out in the boat. You guessed it - struggled to get it to align. I eventually managed to get a smooth low pressure alignment tool insertion so I rotateed the crank 180 degrees by hand and tried again. No chance, the alignment tool bound up immediately and I could not get more than about 5mm of insertion.
Am I just extremely unlucky or has anyone else had recent problems with poor quality engine couplers. Or am I doing something fundamentally wrong.
I am an experienced engineer but I'm relatively new to boat engines.
Any help or insight would be much appreciated.
Wayne
