SPS Thai Longtail Performance



Ease of Use



The SPS brand is very competitive and dominates longtail racing in Thailand. The current fastest longtail race boat in Thailand ran a top speed of 119 mph using SPS drivetrain parts. Swamp Runner owners benefit from that racing experience and enjoy exclusive access to numerous performance parts and propellers.

Performance Props

At Swamp Runner, we offer the largest assortment of performance props of any mud motor company:

The video below features an 1836 riveted jon boat with a 22hp predator engine going 30-mph. The engine has an aftermarket exhaust, but everything else is stock. This boat was running our 8.5″ Hurricane Prop.

Our performance propellers are not the only reason a Swamp Runner is so speedy.  To learn more, read why a Swamp Runner is faster & runs more shallow than all other mud motors.  


There are two different types of longtail mud motors; Thai Longtails and American Longtails. With the same hull, same payload, and equal horsepower, a Thai longtail that is built correctly will ALWAYS outperform an American longtail.

The older, time-tested Thai design will not only be faster, but will also run more shallow through the water than the American version.  Why is that? 
The mechanics of how a Thai longtail operates is very different from how American longtails function.  There are several design differences that make the Thai version superior.

  1. Longer Shaft vs Shorter Shaft – The longer shaft of a Thai longtail points more in line with the forward direction the boat hull is traveling. The shorter shaft of the American design creates a steeper shaft angle, that directs propeller thrust more skyward, and less toward the intended direction the boat wants to move. The more efficient shaft angle of the Thai longtail makes it faster.
  2. Surface Piercing Propellers – The longer shaft of a Thai longtail is also what allows the prop to run higher through the water than other mud motors. Thai longtail props run on the surface, in the crested water where the two wakes meet behind the boat, which is higher than all surface water around it. All other mud motor props run subsurface in the water directly behind and lower than the bottom of the boat.

    3. Direct Drive vs U-Joint – The shaft of the Thai longtail is in direct alignment with the output shaft of the engine which is the most efficient way to transfer horsepower to the prop. The American design utilizes a U-joint to redirect power to the prop in a different direction from the engine output shaft.  The resulting difference in shaft angle robs the American longtail of horsepower and is far less efficient when compared to the inline connection of the Thai longtail.
    4. Cavitation Plate / Ride Plate – The Thai longtail has less drag when compared to an American longtail because it does not need a “ride plate” or “cavitation plate” that the American longtail depends upon to operate. The steep shaft angle of an American longtail requires a “cavitation plate” or “ride plate” over the propeller in order to force the shaft downward in the water and keep the prop submerged.  Without this plate, the prop would climb out of the water and be unmanageable. Unfortunately this plate also creates significant drag and can catch weeds.  Thai longtails do not need this plate, so their sleek design has minimal drag and slips through the water with less effort.


Performance and durability go hand in hand.

  • Swamp Runner has a bushing that will withstand countless hours of abuse in rough terrain and will outlast any other bushing or bearing in the mud motor world. We ran it for over 1,000 hours at wide open throttle and saw no visible wear. The competition has nothing like it. Little maintenance, inexpensive, long lasting. Learn more …
  • At Swamp Runner, our coupler housings, engine bases, gimbal brackets, and transom mounts all have two layers of protection against corrosion to improve their durability. Step one, we electroplate them with Zinc. Step two, we give them a high-quality powder coating.

Ease of Use

Drive for hours and still be able to hold your shotgun up.

  • The Swamp Runner longtail mud motor kit is designed to sit as low as possible to the water. This decreases the shaft angle and allows the longtail to ride the way it was designed too, easily.
  • Our engine & gimbal bracket pivot on a high quality, sealed Japanese bearing which allows you to drive the longtail with ease and this also helps prolong the longevity of the other kit components.
  • The SPS longtail kit comes with adjustment holes so you can balance your kit for your unique boat & engine combo. Most other mud motor brands have no adjustability. 


Designed simple, so there isn’t much you can’t fix in the field.

  •   The SPS Swamp Runner longtail mud motor kits are designed to give you the best performance along with the most reliability. Our parts are easy to assemble, replace, or even upgrade. No need for a special mechanic or expensive tools. Keeping it simple means fewer parts to break.
  • You built the kit yourself and read the owners manual, so you’ll understand how it operates, and have peace of mind knowing there isn’t much that could go wrong or easily fix it in the field.
  • Mud motors operate in very shallow water where there is a high potential to hit hard objects like rocks and stumps. When you are running in shallow water, its not a matter of IF, but WHEN you are going to hit something.  To protect the drivetrain, there needs to be a sacrificial part that is both affordable, and easily replaced in the field. We believe the propeller should be the weakest link in a mud motor drivetrain, not the strongest. Our reasoning; its a lot easier to replace a bent or broken propeller in a few minutes, for just a few dollars, than to be stranded in the middle of nowhere, and have to replace a bent or broken shaft with a lot more money and effort involved.
  • We use Swamp Runners for our caribou/moose hunts in Alaska, where we run remote rocky rivers.
    Round trip hunts usually average around 350 miles from civilization back to civilization.

    On remote trips like that, there is no way to call anyone for help, so a broken shaft is not an option. 
    We run aluminum propellers for this very reason.
    The propeller is the sacrificial part in the drive train because;
    1. It’s easy to change out in the field.
    2. It’s the most affordable part in the drive train to replace.
    Last year we carried multiple props with us, but ended up running the same prop for two trips totaling over 700 miles.
    This is just one example of why we say our longtails are Built For the Middle of Nowhere.

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