Hi. I bought a used 1988 cruiser with twin Mercruiser 454's and inline velvet drives/transmissions (72C, 1.91 gear ratio). I was told the current drives are not functioning properly by the current owner prior to purchase, the engines run fine. however, the previous owner never put it in the water and has no idea what is or isn't wrong with the velvet drives.
So... I am getting it working with the help of a mechanic friend of mine (not a full-time marine mechanic but a very good auto/engine guy). He's done lots of work on I/O's butnot as familiar with inboards. So I have some questions.
It COULD be that the drives are indexed for the wrong rotation of engine and only need to be switched. However, it could also be they need replacing or rebuilding. I researched as much as i could find and know these drives can be used on either a RH or LH motor, but need to be set up for whichever they are on. Either way they reverse the rotation to the prop. THAT much I get.
My question is, how do I know if they are working without testing while the boat is on blocks? Can I engage them without cooling water ? I know I need the water to the engine and I know how to dothat now, but the drive and bearings also? Need two hoses?
So, assume I can test them on land then I get them working. I read they should get final alignment after the boat has been in the water for a day or two. This boat sat on blocks for two years so I think I should follow that advice. How do i align them to test then? I don't want to launch it THEN find out the drives still aren't working.
Any help or links to instructions would be appreciated.
Thx.
So... I am getting it working with the help of a mechanic friend of mine (not a full-time marine mechanic but a very good auto/engine guy). He's done lots of work on I/O's butnot as familiar with inboards. So I have some questions.
It COULD be that the drives are indexed for the wrong rotation of engine and only need to be switched. However, it could also be they need replacing or rebuilding. I researched as much as i could find and know these drives can be used on either a RH or LH motor, but need to be set up for whichever they are on. Either way they reverse the rotation to the prop. THAT much I get.
My question is, how do I know if they are working without testing while the boat is on blocks? Can I engage them without cooling water ? I know I need the water to the engine and I know how to dothat now, but the drive and bearings also? Need two hoses?
So, assume I can test them on land then I get them working. I read they should get final alignment after the boat has been in the water for a day or two. This boat sat on blocks for two years so I think I should follow that advice. How do i align them to test then? I don't want to launch it THEN find out the drives still aren't working.
Any help or links to instructions would be appreciated.
Thx.