M80 & M120 Trim Tab Installation Guide Page1

Tools and Materials List:
7/16", 1/2" Wrench	Small Funnel
Electric Drill	Wire Stripper
Two Foot Straightedge	1 1/8" Hole Saw
Marine Grade Sealant	Tape Measure
Masking Tape	Wire Cutters
9/64", 3/32", 5/32", 3/16", and 3/4" Drill Bits	#2 and 3 Phillips Head Screwdriver
Automatic Transmission Fluid	Regular Flat Head Screwdriver

Step 1 - Position the trim tabs against the transom and check to see that the upper mounts of the hydraulic actuators do not center on an inside obstruction. If they do, reposition the tabs slightly outboard. The further outboard the tabs are mounted the greater the lateral (side to side) control. Position tabs 3 to 4 inches from the chine, and a minimum of 8" from the centerline of the outboard or sterndrive unit (see Picture 1 and Figure 1). Note: If the inside of the transom is inaccessible due to a fuel tank, flotation, or other obstruction, call for alternate installation options. (1" shorter actuators are also available.) Click here to see images of alternate mounting options.

Step 2 - Attach the mounting plates and trim plane with #10 x 1-1/4" stainless steel screws 1/4" above the hull bottom (see Figure 2). Using the backing plate as a template, mark screw hole locations (see Picture 2 and Picture 3). Drill 9/64" pilot holes for mounting screws. Test to see how the screws fit. Enlarge with 5/32" drill if needed. Assemble mounting plates and tap, dip screws in marine epoxy before tightening them. Slide trim tab between backing plate and hinge plate before running screws tight. Snug screws down to secure mounting plates and trim tab to transom. Aluminum boats should use machine screws and nuts (not included) instead of the enclosed #10 self-tapping screws.

Step 3 - Secure the lower hinge of the actuator to the port trim tab using 1/4-20 x 3/4" machine screws. Using a straightedge under the trim tab and hull bottom, set the corner of the tab trailing edge to 5/8" negative (see Figure 2 and Picture 4). With the tab set at this 5/8" negative angle, position the upper mount of the actuator against the transom. Slide the actuator template behind the upper mount, align and tape to the transom. It is not necessary that the upper mounts lie flat against the transom as the actuator neck has the ability to flex far more than necessary (see Figure 3). The straightedge may now be removed. Drill holes accurately as indicated on templates. Drilling a small pilot hole first helps you locate accurate centers. Repeat for the starboard side.

Step 4 - Screw brass fitting with attached tubing into the upper mount of the actuator. Tighten the fitting only snug with a 7/16" wrench. Do not attempt to "bottom out" the fitting (see Picture 5 and Figure 4).