Sport C Racing Power Trim System

 

Power trim systems are custom built for these race boats. Any stock trim system equipped on an engine from Tohatsu won't be fast enough for racing needs. The systems consist of a few brackets, a trim ram (commonly scavanged off a small outboard), a power trim pump (such as a mercruiser sterndrive unit), trim indicator (cable), and trim switches or buttons.

Trim SsytemMany varieties of trim rams will get the job done. The compact rams off smaller mercury outboards of years past are very popular. The local used parts yard, ebay, and similar are common sources.

There are two options for the boat side of the trim ram. One is to mount it to the transom or a bulkhead in the boat. The other is to mount it to the jack plate assembly. The advantage of mounting to the jack plate is motor height adjustments don't affect trim geometery or the trim indicator. Another disadvantage of mounting the the transom (typically inside with the ram penetrating through a large cutout) is that water must be keep out of the boat somehow. A rubber shifter boot attached to the transom and zip tied or clamped to the ram outer end works ok but still allows seepage while waiting for a heat to start. A better option is to fiberglass in a watertight bulkhead forward of the ram hardware. The resulting ram compartment may flood. However, it keeps the rest of the boat from filling with water.

Race Boat Trim

Attaching the ram to the motor is a custom project. A few have an aluminum bracket welded to the outboard. This can be an elegant solution, but also requires dismanteling the swivel bracket assembly, and careful welding to avoid heat warping the motor. Another option is to bend pieces of aluminum plate and bolt them to the motor.

Race motor trim bracket

 

 

 

 

Boat Trim

 

 

The next component is the hydraulic pump. A mercruiser style stern drive trim pump works well. Sierra builds an aftermarket and readily available unit with reservoir and solenoids. Sierra Trim Pump