Laser or string on centerline of shaft for engine location/shaft alignment


Aug 6, 2013
Southwestern CT
First Name
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
Anyone use any of these techniques? I have seen it used in repowers/new builds and it makes sense since the whole world has to be planned around the location of the engine and gear and that is determined by the alignment with the shaft.

I understand how it would allow you to get the output flange from your gear centered on a line that is centered through your cutlass/tube/babbit or whatever you have (center line of shaft) but the output flange of the gear has to be square to this line on 2 axis. Are you just working with the angle finder for this last part when laying out a new installation or what?

My understanding- The string is set through the tube and bearings and engine has to meet that with down angle or straight gear. Installer gets to decide where along that line the engine will go (forward and back) to balance boat, stay below deck beams or whatever and the angle of the engine to the shaft is just determined using the angle finder. Right?

Can someone walk me through this approach and the logic behind it? Think I got but thought I would ask.
Top Bottom