seadoo sportjet..

[jpoole]

a buddy has one of these boats looks to be a carbed 2.4 or 2.5 inboard onto the jet pump. all we can manage with one person is 5500 rpms. is there any way to increase rpms to get more top end. i kno these motors had one of each on a bullet and they are good to atleast 6500 to 7 grand without any problems.. anything i can do would be appreciated

[Jay Smith]

Several years ago I was contracted to build a couple of the Sportjet engines for a race team in Canada. We found that the pumps were limited to turn NO MORE than 6000 rpms PERIOD. Turning the engine more than 6000 rpms was found to be a mute point..

Target the motor to turn no more than 6000 and have a more aggressive pump auger ( impeller ) built , tighten up the clearances between the housing and the auger and it will gain MPH.

I worked on making more compression and cut the front case half all with low end torque at a top rpm of 6000 in mind and the engines were successfull racing and won all that season with that combo.. The Sportjets engines I built engines were installed in white water boats ..

Good luck,
Jay