Rotax 1503 motor question

[McCriding]

Hi guys,
I'm looking for a little guidance. I have a 2020 river raptor (small custom boat builder here in central PA) xr1960 jet boat that I ordered with a150hp rotax 1503 engine. I love the boat but walked into a great opportunity to get something with a 250 so I'm listing it for sale and have been getting a lot of questions about whether it can be converted to a200 or 250. Which brings me to my questions...
1. Are the 150-250 the same block and internals just NA, supercharged, and supercharged and intercooled?
2. Is it possible to upgrade or add a supercharger to this engine?
3. If it is possible does anything else have to be changed to actually see any benefits from the increased power?
Thanks in advance for any advice you guys can provide.
Cheers!

 

[Sidarousmg]

my understanding is (and i could be wrong), they are all the same block/internals, but i've never heard of an NA engine being supercharged after the fact. plenty have been upgraded from 200 to 250 (external intercooler, fuel injectors, upgraded supercharger) but i don't think you can just slap some parts on the NA engine to supercharge it. on the seadoo and scarab boats, there are significant gains from 200 to the 250, but they share the same size impeller. i believe the 150 used a smaller size impeller, so that may restrict any potential power gains if they were added.

 

[McCriding]

Thanks for the info. I think you are correct. Do you happen to know if it's possible to just do a full engine swap without having to cut anything out of the bottom of the boat?

 

[Sidarousmg]

Thanks for the info. I think you are correct. Do you happen to know if it's possible to just do a full engine swap without having to cut anything out of the bottom of the boat?

i really don't know, i would think that depends more on the boat (which i'm unfamiliar with) than the motor. but again, even if you were able to easily replace the motor with a more powerful version, the drive system (impeller and housing) would still be the same size, which will limit how much power you can actually deliver to the water.

 

[ScarabMike]

Same block, different internals. You could swap them out, but there will be some plumbing differences (intercooler/air intake), and you will need the supercharged motor's ECU. Also if there is a custom dash, you will have to marry it to the ECU with the help of someone with a Candoo Pro, or taking it to the dealership. Its very doable, and you'll have a rocket.