Max rpm with a Scarab 165…

[Divouneh]

With my Scarab 165 (75 hrs today); I never keep full trottle (except when starting with a skier).
The max rpm for the engine (I have the 170hp) looks to be 8000rpm and full throttle will go further . Max speed will be around 42 mph …

 

[Luc Lafreniere]

Most of the specs are listed here: https://www.scarabjetboats.com/uploads/2024/9/ScarabPIG2024v4.pdf

But yes, 42 = top speed for the 170. I sometimes get that with my 150HP if I didn't eat too much that day and the wind is in the right direction.

 

[Divouneh]

Hi Luc : Speed is ok for me, punch to however I never stay to full gaz due to the over speed from my engine. My question was : do we have (probably) a max rpm we could go with my Rotax ?
We probably have an electronic protection …

 

[Luc Lafreniere]

Yes. Your engine capped. The max RPM depends on the engine's HP.

I think for most engines, the idle RPM is 1750.

The maximums:

150HP is 7300
200/250HP is 8000

These numbers are from the service manual. There's also a limiter at 7750 for 150HP and 8300 for 200/250HP.

I don't have the manuals for the latest 170 and 230HP engines, but if you can find them, it'll be posted in there or hopefully someone else can chime with those numbers.

 

[Divouneh]

I have the 8000 in mind, I will ask to my mechanic …

 

[BumbleBee255]

My Rotax ACE 170hp maxed out at 7600 rpm.