Help pls How can I determine hp in newly purchased boat?

[newb]

Hi,
thanks for your help. I recently purchased what was advertised as a 2015 Scarab 165 ID with 250 hp. Now that I have it here and am out on the water in it I do not think it is 250 hp. It tops out with just me in the boat at about 35 -40km hour. I was driving a 2018 at 300hp and it was much faster. Is there somewhere I can look that will identify the HP on the boat or somewhere I can look it up by serial number? It was a good price for a 250hp but not at all for a 150hp.
Thanks

 

[Luc Lafreniere]

I've got the 150HP. I get about 42 MPH, not KPH. So 67 km/h. Do you mean 35-40 mph maybe? If so, that indeed sounds like the 150HP unless you've got some impeller or wear ring damage (or something else). Do you have a supercharger? Take a pic of the engine bay, good clear shot and that will help us. If the boat is out of the water, take a few CLEAR pictures through the intake grate under the boat. Make sure to have good lighting so we can see the edges of the impeller as well as the plastic wear ring around it. You can also take a pic through the jet nozzle at the stern looking inside. You should see the impeller and wear ring from that angle as well with good lighting.

 

[Dean P]

Rotax has picture of their various power plants. You can compare yours to theirs.

 

[Gozills]

250 should have catalytic converter and external intercooler

 

[Winerocks]

Can you post some pics of the engine? Get a shot of the very back if you can.

 

[Winerocks]

Bit late, but here's a pic of a 250HP Rotax with the identifiers circled. The intercooler is a bit hard to see in the pic, but it is a shiny aluminum box tucked behind the engine, with a big black hose attached at each side.

 

[newb]

Thanks to everyone! So much information before I even got the photos off my camera