Jet boat newbie here!

[maynard7]

Hi all,

I just purchased a 2022 Scarab 165 ID which I will be using around the Choctawhatchee Bay area. I took it out yesterday for the first time and it was and didnt stay long because it was a bit rough. Waves were about a foot high with 15 mph wind. I guess I'm going to have to take it out a few more times to get a good read on what kind of weather will permit a smother(er) ride because I nearly gave my wife ptsd on that trip. My question is about the speed of the boat and the rpms. This has the Rotax 170 in it and I could only get it up to about 10 mph at 5000 rpms. Do I have to redline this thing to get decent speed out of it and is that typical of a jet boat? I didn't want to blow it up on my first trip.

 

[Luc Lafreniere]

Here's the Scarab chart the 165, 170HP. 5000 rpm = 9mph. The next step is a large one at 5500 rpm, suddenly 22mph.

 

[maynard7]

Here's the Scarab chart the 165, 170HP. 5000 rpm = 9mph. The next step is a large one at 5500 rpm, suddenly 22mph.

View attachment 175365

That is awesome! Thank you! Amazing how much 500 rpms can make. I'm assuming that's when the boat get "on plane"?

 

[Luc Lafreniere]

Yeah, I assume the same thing. I have the 150HP. I don't remember exact when it gets on plane, but it's around there. Obviously depends on weight and distribution of weight.

 

[HawaiiBreeze]

Congratulations on the new Jet Boat!

 

[Divouneh]

Very interesting, datas. In my (2023) 170 HP I reach more than 8000 rpm and around 41 mph (never done full speed test).
Could come from a different propeller , 7000 rpm was the max in braking time.
6000/6500 rpm looks to be the best, we have to watch the miles / galon.
4.7 mpg with 15 gallons gas tank (to be safe : reserve 5 Gallons) means 70 miles range .
Soon I will have more data from my boat ...