For proper operation of the engine, the propeller shaft and engine must be aligned.
Alignment is gauged at the engine and shaft coupling. Alignment procedures must be done with the boat in the water after the mast is stepped and the rig is tuned.
1. Remove coupling flange bolts and check propeller shaft for clearance. Adjust stuffing box so that excessive seepage is prevented, yet the shaft is allowed to spin freely.
2. Slide shaft away from engine and check coupling mating surfaces. These must be clean.
3. Slide shaft forward to connect coupling surfaces. Pilot on transmission flange must align with recess in shaft coupling flange. This is an indication of correct axial alignment.
4. With coupling flanges in contact, measure gap around edge of coupling flanges with .003 feeler gauge. Maximum allowable gap at any point is three thousandths of an inch. Take this measurement several times ... rotating shaft 1/4 turn each time. Any gap in excess of .003 must be corrected by changing engine position, especially fore/aft tilt.
For example, excessive gap at the bottom of the coupling (see drawing) indicates engine is tilted too far aft (front too high). Using a 15/16 end wrench, loosen lock nuts on forward
motor mount(s)@ Lower front of engine by clockwise rotation of motor mount nuts. Re-measure gap at coupling. A gap at the top of the coupling would require the-exact reverse procedure.
5. Pull shaft aft as in step 3. Again slide shaft forward, rechecking axial alignment as in step 4.
6. Repeat steps 5 and 6 until alignment within tolerance is achieved.
7. Tighten motor mount lock nuts and install coupling.
NOTE: Alignment should be checked yearly, or whenever any excess vibration is noticed. The alignment can also be affected by changes in rigging tension.
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