Sea doo spark engine swap to a ROTAX 1503 NA 4-TEC


i am looking at making my spark much faster mainly in the 0 to 60 area. i have looked at a turbo but having worked on cars for a long time i was considering just going to a bigger engine, as it may be simpler in some ways. i was wondering if anyone had looked into this and if it will fit. also thinking i want it to be reliable. thank you.


Unlike a car, the engine bay isn’t nearly as forgiving for a swap. You’ll not likely be able to fit anything else inside as the clearances for the hull were designed around this engine.

Turbo is certainly the more affordable route for more power…but if you were able to figure out fitting a 4tec into a Spark, I’d love to see how it was done!


ya those are all my concerns with swapping the engine. this is going to be a winter project but i was all so wondering if any one knows what the stock compression is for a rotax ace 900 ho.


Off the top of my head I’m pretty sure it’s 12:1.