TMM 20-15 Transom Motor Mount for Long and Short Shaft Outboard Motors
The TMM 20-15 is a versatile transom mount that fits both 20″ long propeller shaft outboard motors and 15″ short ones - Just flip and relocate it, and it’s ready for the new motor.
- Price: $138.
No extra charge when shipped together with a W kayak
When shipped separately: $20 S&H in the continental US (48 states)
When shipped separately: $25 S&H to Canada and Alaska
Materials and Construction
The TMM 20-15 is made from 3/4″ thick Medium Density Overlay (MDO), a composite wood and polymer resin (a.k.a. plastic) material developed for outdoor use such as signs and marine applications. The front and back of the MDO panels come coated with a waterproof polymer-infused layer, and the sides of the parts that form the TMM 20-15 are waterproofed with polyurethane. Unlike the TMM 20 and TMM 15 specialized motor mounts that are made from Trex, which is a heavier material, the MDO used in the construction of the TMM 20-15 makes it considerably lighter.
The parts from which the TMM 20-15 is made are cut with a computerized router for maximal precision, best fit, and optimal strength. They are assembled and glued together with waterproof adhesive. The tab-and-slot technique and ‘caisson’ design applied in this product give it additional strength.
There is no need to paint this motor mount, but in case you want to, it can be painted with special paint for outdoor plastic, such as Krylon Fusion spray paint. Regular paint doesn’t adhere well to its surface.
The bolts, washers and nuts used in this motor mount are made from zinc plated steel.
Dimensions and Technical Specifications
- Width: 21.5″ (54.5 cm)
- Height: 5.5″ (14 cm)
- Depth: 7.5″ (19 cm)
- Weight: 2.5 lbs (1.14 kg)
- Horsepower Compliance: This design was tested with small outboard gas motors such as commonly used with Wavewalk 500 kayaks. It is unknown whether this product fits heavier and more powerful motors in the 4-6 hp range, which aren’t recommended for use together with this watercraft in any case.
How to attach this motor mount to your W kayak
In the 20″ position, just put the mount as close as possible to the rear end of the cockpit, as seen in the picture below, make sure it is centered, mark the two spots where you’d need to drill 3/8″ holes for the blots, and drill.
In the 15″ position, the distance of the motor mount from the rear end of the cockpit will be determined by the bolts that attach the motor to the mount, and the position of the motor when the propeller is. You’d need to make sure that the motor can tilt all the way down and lock, as the propeller shafts rises up from the water. You’d also need to make sure you can fasten and release the bolts that attach the motor to the mount.
Once this is done, make sure the motor mount is centered, and mark to two spots whee you need to drill the 3/8″ holes for the mount’s bolts.
Bolt the motor mount in its place by tightening the nut knobs with their Tee nuts facing down.
Why a dual purpose motor mount?
The problem starts with the fact that only a handful of small outboard motor models feature a 20″ shaft, which is the preferred length for the W500. This limit in choice forces some W owners to use a 15″ (short) shaft motor. If later they find a 20″ (long-shaft) outboard, having a dual motor mount would save them the need to get a new motor mount for it.
Other users may want to use an outboard gas engine for long drives, or when they go through rough water, where electric motors aren’t recommended (see article » ), and use an electric motor when they fish in flat water and in no-motor zones (NMZ). Having a mount that can accommodate either type of propulsion can save them the need to carry and install two motor mounts on their W.
We also had our dealers in mind when we designed this motor mount. It’s easier for them to have one type of mount in stock rather than manage two different items. In the long run, this would improve the service our clients get from our local dealers and distributors.