Tag Archives: outboard gas engine

Transom mount for long and short shaft outboard motors

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.
  • Shipping:

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.

TMM 20-15 Transom Motor Mount in the 20″ (long) position


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.

TMM 20-15 Transom Motor Mount in the 15″ (short) position
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.

More about motorizing your kayak »

My Wavewalk fishing kayak with a 2.5 Suzuki outboard motor, by Robert Buck

I have had the kayak out twice so far. The first time was for about an hour and did not go too far. I went out on Friday to a lake and was on the water for about 4 hours and went about 4 1/2 miles. It was a beautiful day on the lake.

It does not take long to get used to using the kayak. This is going to be great for what I bought it for and that is fishing. I can carry all my equipment and move around and change hooks and lures easily.
Had to paddle into a little wind on the way back on Friday. No problem as the kayak cut through the waves and no bouncing over the waves.
I am happy with my purchase and plan on getting out even more now.

When I picked up the Kayak and we had it in the van, I could not see out the right hand window so when I arrived at my friends I strapped it to the roof. I was worried that I would not be able to see vehicles coming onto the highway from entrance ramps. I have now got it down pat to strap to the roof. The eye hooks on the motor mount work great for strapping down one end of the kayak.

I had the motor on the Kayak for the first time today. Must say it takes a little getting used to but did great.

Just one point though, the mount for the short shaft motor should be placed to the rear a little more as the motor will not tilt up and lock in place. I think the tension screw will be enough to hold it up so it does not fall back into the water. I had no problem with it staying in place.

I do have a video from yesterday as this was my first time with the motor:
I was impressed with the way the kayak cut though the waves. There was no bouncing around going through the waves.

It takes a little getting used to using the motor. I like the fact that I have the option of using a motor. It just makes the kayak more versatile.
I do like it better without the motor, but the motor will have its time and place when using the kayak.


Robert Buck
Saint John, New Brunswick, Canada

My Wavewalk fishing kayak and tackle box




More fishing kayak reviews »

13 mph in my W motorized kayak with a 6 hp outboard motor, my speed record (unofficial), by Kenny (One-Shot) Tracy

Finally, I was able to try out my new motor. It was a little hard getting it started, but after that, it ran fine.

In officially, I am the new speed record holder in a W boat! I used my IPhone app, and it said I was doing 13 mph! I had two friends who witnessed it from shore, who said that I might need some ballast up front to keep the nose out the air! I was sitting on the middle in my seat, and didn’t feel the least bit “out of control”, in fact it was quite smooth! I am going to make some trim adjustments, because my transom did get a little “low” in the water. I was not using a third of the throttle yet, ( still doing the “break-in thing), but as I gave it a little more throttle, my motor mount cracked almost in half! Thankfully, I had tied a small rope around the motor to an eyelet up closer to the original transom area, so I was able to let it “idle” and get it back to the dock. The pictures show the damage.

I think the foam (sides), may be a game changer. There was not one bit of wavering from side to side as my speed increased. I was sitting directly in the middle of the cockpit, and steering with a U-joint tiller extension.

Okay. Next is to scrap my seat, get another motor mount, and adjust my trim… I should have my Hero 3 camera set-up and mounted by then to have tangible evidence of my speed claim as well.

Kenny “One-Shot”

motorized-kayak-broken-motor-mount-due-to-overpower motorized-kayak's-motor-mount-broken-by overpowerful-outboard-motor

More about One-Shot’s motorized kayak project >

Test fitting 6hp motor on my W kayak, by Kenny (One-Shot) Tracy

Got my motor in last week. It’s a 6-hp Tohatsu Sail-Pro with a 20″ shaft and a 5 amp alternator. I’m going to mount my gas tank at the very front end of the saddle to help balance it out. I’m going to purchase a small battery and mount it in the rear to run my lights and fish finder. I ordered a go-pro camera and a mount, so I’ll (hopefully) be able to send you some action shots in a couple of weeks.

Thanks again for all of your support. I’ll send more photos after I get it rigged up, before I put it in the water.

Even though I ordered the 20″ shaft, does the cavitation plate look a little low to you?


6hp-outboard-motor-on-fishing-kayak fishing-kayak-with-6hp-outboard-motor motorized-kayak-with-6hp-tohatsu-outboard

More from Kenny “One-Shot” Tracy >

Windshield style spray deflector for motorized fishing kayak

This can be an interesting DIY project for a fisher who owns a W kayak outfitted with a gas outboard motor who’s looking to prevent spray from getting into the cockpit while driving through waves at high speed, or when a strong frontal wind blows spray in.
It’s a cool alternative to using a tarp as a cockpit cover.
Attaching and detaching it takes a few seconds, and it can be done from within the kayak’s cockpit, while the fisher is on the water.
Storing this windshield on board is easy too. It’s just a 4ft long and 1ft high, lightweight plastic board that fits in one of the W kayak’s hull tips.

The crystal clear transparent material used for it is 0.096″ thick Acrylite, and its dimensions are 48″ x 12″. It’s a bit hard to cut without breaking it, but working with a box cutter eventually creates a groove deep enough for breaking the board along the line. You can also cut it with a jigsaw that has a thin blade with small teeth.

This windshield style spray deflector is then outfitted with lashing hooks that allow for attaching it to the top front part of the cockpit by using the bungee cord and hooks that are already in place as part as the preparation for cockpit cover (tarp). You may need to tighten the bungee (shock cord) in order to make it hold the windshield better.

windshield for motorized fishing kayak windshield for motorized fishing kayak windshield for motorized fishing kayak

More about outfitting your W fishing kayak »