Max-Prop Classic 3 Blade — Installation & Removal Instructions

Pitch Setting

• Pitch is adjustable from 10 – 30 degrees of blade angle, set with the propeller mounted on the shaft.
• Find your diameter column, go down to the pitch in inches you want, and read the blade angle across (Fig. 1).
• Engine short of the desired RPM: reduce the blade angle. Over-revving: increase it.
• A two degree change in blade angle changes engine RPM by 13% – 15% at the same boat speed.

Assembly

Each propeller is individually balanced: never swap parts between propellers. Numbers refer to Fig. 2.

• Hub (1) must slide fully onto the shaft (2); file the key (3) if it stops short of your mark.
• Drilled nut: tighten the nut (4) and pin it by drilling through nut and shaft. No-drill nut: align the grooves with the hub, insert and rotate the pins (5) clear of the cone gear.
• No more than one thread exposed aft of the nut; cut off any excess or it raises the central cone gear (6).
• The grooved tooth on the central gear is the "X": seat it in the hub letter given by Fig. 3.
• Fill both spinner (7) halves with sea-water grease (Lubraplate "130 AA"), close them round the hub. Do not use Teflon grease.
• Turn the spinner until its "Y" drill mark lines up with the cone-gear letter from Fig. 4. Mark spinner and hub so any rotation shows.
• Fit the blades on the spacer (10) pins, grease the end cap (11), slide on with blades feathered (rounded trailing edges aft) and numbers matching 1-1, 2-2, 3-3.
• Bed the parts with a plastic or wooden mallet; lock each screw with a 1/16" stainless cotter pin cut to 1/4".
• Protect with zinc anodes on the shaft and on the end cap.

Maintenance

• Regrease at least once every two years with Lubraplate "130 AA".
• Remove the forward set screw with a #3 metric Allen wrench, fit the zerc tower and pump until grease shows between hub (1) and spinner (7). Repeat at the aft hole until grease shows between blades and spinner.
• Rotate the propeller from forward to reverse with each pump. Never leave the zerc tower in.
• Replace the zinc anodes at least once a year, cleaning the contact faces with a wire brush or fine sandpaper.

Troubleshooting

• Stiff rotation: remove some grease from the spinner and reassemble.
• Hard spots (burr or ding): reassemble without the central cone gear (6). If the hub is hard, remove 0.01 mm from surfaces "A"; if the blades are hard, remove 0.01 mm from surfaces "B" of the spacer.
• Refit the cone gear. If hard points remain, remove 0.1 mm from surface (C) so the gear sits lower.

Removal

• Feather the blades and mark spinner and hub.
• Remove the zinc and the 6 end cap bolts; slide the end cap and blades off together.
• Note the cone-gear letter at the "Y" drill mark (record as Y).
• Remove the four spinner bolts and the spinner halves. Do not remove the central cone gear yet.
• Mark cone gear to hub, then read the hub letter at the cone-gear punch mark (record as X). Remove the cone gear.
• Remove the nut pins, back the nut off one turn (leave it on), and pull the hub with a puller bearing only on the outside of the hub.