Max-Prop Easy SailDrive (2, 3 & 4 Blade) — Instruction Manual

Installation

1. Fit the propeller onto the spline like a fixed propeller, with the thrust washer on the spline first. Without the thrust washer the propeller is loose fore and aft on the spline and will damage the SailDrive or the propeller.
2. Firmly tighten the nut. Align the holes in the back of the nut with the grooves in the central hub and tighten the two shaft nut lock screws. Insert and tighten the center locking bolt into the back of the nut and secure it with its set screw. Loctite blue on these locking bolts is optional.
3. Fit the zinc with the three Allen bolts; zinc and propeller must be clean for good contact.
4. Fill the propeller with the supplied marine grease through the (3 to 4) holes marked "GREASE", using the supplied grease fitting, following the illustrated sequence 4.1 to 4.9 and repeating with the forward fitting. The central body must be completely full: grease must ooze from the rotating joints between the central part and the hub. Use only a Max-Prop approved grease that stays fluid for years and does not stiffen in cold water; Max-Prop recommends Lubriplate 130AA (calcium based, NLGI 1).
5. Check the blades are lined up correctly in the feathered position.

Before Launching

• Hold the propeller shaft and check that the blades rotate freely from forward to reverse with a light effort.
• In the feathered position the blades must be perfectly lined up.
• Confirm the propeller body is full of grease.
• Protect the propeller from galvanic corrosion with sacrificial anodes on the propeller and on the shaft.

Pitch Adjustment

Fig.3: pitch in inches for each blade angle (rows) and propeller diameter (columns). Size diameter and pitch as for a fixed propeller, find your diameter column, go down to the pitch you need and read the blade angle across.

• Supplied with 5 forward pitch bolts (16, 18, 20, 22 and 26 degrees blade angle) and 3 reverse pitch bolts (#1 = 14 degrees, #2 = 20 degrees, #3 = 24 degrees). Example: the #20 bolt in the forward bore plus #2 in reverse gives 20° in both directions.
• If the engine does not reach the desired RPM, reduce the blade angle; if it exceeds it, increase the blade angle. One 2° step changes engine RPM by about 13% at the same boat speed.
• The body has two threaded bores marked "R" and "L", each with a pitch bolt. Forward pitch is set by the bolt in bore "R" on a right-hand propeller, or in bore "L" on a left-hand one.
• Rotation is judged from the stern looking forward with the engine in forward: clockwise = right hand "R", counterclockwise = left hand "L".
• A lost pitch bolt can be replaced; the correct size needs the propeller serial number, stamped into the zinc bearing ring under the anode.

Micro adjustment with the existing bolt

• With the existing bolt you can lower forward pitch and increase reverse pitch. A higher forward angle (bolt already fully engaged) or a lower reverse angle needs a longer bolt.
• Forward: a 1/4 counterclockwise turn reduces the blade angle by 1/2 degree (about 3.25% more engine RPM at a given boat speed); one full turn reduces it by 2 degrees, two full turns by 4 degrees.
• Mark the bolt position and its orientation to the locking set screw, remove the locking set screw, loosen the pitch bolt by the amount needed and lock it again with the set screw. The same method increases the reverse blade angle.

Changing the Rotation

1. Place the propeller in the feathered position; unscrew the zinc locking screws and remove the zinc.
2. Unscrew the nut locking screws and remove the nut.
3. On the aft side of the hub one tooth carries a reference mark; the zinc bearing ring has one tooth marked "L" and one marked "R", one of them aligned with the mark.
4. Remove the circlip on the aft edge of the hub.
5. Remove the zinc bearing ring.
6. Refit the ring with the "L" tooth on the hub reference mark for a left-hand propeller, or the "R" tooth for a right-hand propeller.
7. Refit the circlip in its seat.
8. Tighten the nut and secure it with the nut locking screws.
9. Refit the zinc with its 3 screws.
10. Change the pitch bolts to suit the new rotation.

Propeller Use

• The propeller works automatically: put the transmission in gear and the blades engage in forward or reverse; they feather from the forward position when you stop the engine and lock the shaft.
• Best way to feather: power at 2 to 3 knots in forward, then kill the engine while still engaged in forward. A properly greased propeller feathers in a fraction of a second once the shaft stops freewheeling.
• Do NOT kill the engine in reverse: the blades stay in the reverse position and cannot feather. You can use this to drive a shaft alternator, or regenerate with an electric motor.
• Mechanical transmission: stop the shaft freewheeling by engaging reverse, only after the engine has stopped completely.
• Hydraulic transmission: shut off the engine while still engaged in forward; the remaining hydraulic pressure locks the shaft for a few moments, enough for the propeller to feather.

Never shift between forward and reverse at high RPM. Idle down and shift at low RPM, or the shock load can damage the teeth of the blade gears and cone gear.