Barrus Shire 90, Original Instruction

Page: 27 / 84

RDG603A23 – Issue 20
Page 27 of 84
9. Engine Alignment
•
The gearbox output shaft flange and propeller shaft input flange must be almost
perfectly aligned. A maximum of 0.05mm (0.002”) misalignment in any plane is
acceptable. Ensure alignment is recheck after the first 4 hours of running, after the first
month and thereafter annually.
•
If the engine is out of alignment it will result in excessive vibration and possible damage
to the stern tube and propeller shaft.
Boats that are fitted with fully flexible drive couplings should still have the engine and
shaft alignment as close as possible. A dummy shaft may be required for this purpose.
Some types of flexible shaft couplings require the input and output to
be misaligned, check with the coupling manufacturer’s installation instructions.
•
Minimum clearance of 25mm between rails and engine beds.
10. Engine Inclination
•
The engine installation angle is the angle of the crankshaft centre to the water line
( Figure 11 ).
•
The propulsion efficiency decreases as the engine installation angle increases.
•
The maximum engine installation angle is 15°
Figure 11: Maximum Engine Installation Angle
Engine Installation Angle
Water Line
MAX 15°