Over the years we’ve seen some pretty crazy LS-swaps at car shows, YouTube, and internet forums. It’s pretty common to see these engines stuffed into exotic cars, hotrods, boats, and even airplanes these days. One thing that we have seen is an LS-swapped personal watercraft. 

An LS-swap personal watercraft or jet ski never really crossed our mind as an option for a few reasons. One problem is the size of the engine and trying to shoehorn a V8 into the watercraft. The second issue is that some of these high-performance jet skis make 300 horsepower with supercharged and turbocharged powerplants comparable to a stock LS engine. Finally, the LS engine weighs a lot more than the factory four-cylinder engines, and mounting it up would be challenging. But all of these issues didn’t stop two guys from attempting this wild swap while documenting the build on YouTube.

The JetSki Brothers decided to tackle an LS-swap with a Yamaha WaveRunner FZR with a GM Vortec engine. In the series of videos, the guys walk us through the entire process. And when we say “walk us through it,” we mean it because there are 17 videos dedicated to nothing but this build. Somehow they not only managed to fit the 4.8-liter V8 in the ski, but they also got it to float and run as well.

You might think that a V8 engine would be hanging out of the sides of the Yamaha, which it does, but the engine cover hides all of the modifications. However, the one thing you can’t hide is the distinct sound of the American-made V8 rumbling along through a custom exhaust system as it echos across the water.

The performance on the LS-swapped Yamaha seems a little underwhelming, but again, the LS is probably making 300 horsepower (65 more horsepower than the factory FZR) with considerably more weight than the factory engine. Don’t get us wrong, it’s still impressive, and the GPS shows the Yamaha pushing right up to the 70 mph mark, which is plenty fast on the water. 

While we consider this project a success, it seems that the guys have plans to try and be the fastest personal watercraft in the future and hint at a turbocharger and more cubic inches. Can you imagine how quick this setup could be with a 76mm single turbo and a custom jet pump? We guarantee with these modifications, 90-percent of the population would not want to go for a ride, and we can’t wait to see it go.