5 replies to this topic

[ZZSDMSMY]

I have posted before about my top rpm's. When I gun it, my rpm's race to 8100 but settle down to about 7200 rpms as i get going. It use to be 6900 rpms before I took it in to the dealer a couple of times. I still have not got a satisfactory anwser why I cant get more than the 7200rpms. Some one outside the Seadoo circle, suggested that the high elevation I am living in would cause this. I am just wondering if anybody knows anything about this?
Thanks!

[ZZSDMSMY]

Well, I took my boat down to Lake Powell this weekend. I found that I got about 100 more rpm's out of my engine top speed. About 7300-7400 rpms at top speed. So I would say elevation has nothing to do with this problem.

I also tested out my speed with a gps unit. I found that my speedometer was really accurate. At 7300 rpm's i was getting 38 to 41 mph, depending on what or who I was carring!

The trip was Fantastic! I thought my boat did reall well down there besides the rpm issue. With a lighter load on board, my wife said the boat had to much pull getting her up on the ski, had to back the throtle off a bit.

[Kevin Leclair]

Thanks for reporting back, it is a good thing to know about the elevation.

[keviseeb]

Thanks for reporting back, it is a good thing to know about the elevation.

Seadoo and Mercury Marine both have high altitude settings for their engines, I know of a Mercury 240 HP EFI that went form sea level to 4,000 ft and it ran so rich at the higher altitude someone called the fire department! Once he got the readjustment the engine ran well again.

Kevin Seeber
Kingsland Marine

[vwDavid]

My sportster SCIC appears to loose less than 100 RPM at Sea level vs. 3500 ft in cold water with 14/19R solas prop.

[kevin3151]

My sportster SCIC appears to loose less than 100 RPM at Sea level vs. 3500 ft in cold water with 14/19R solas prop.

My 06 Challenger 180 tower with a solas 14/19 impeller does 7700 rpm and 44 mph at sea level.

Last week I took it up to Lake Tahoe at 6500 feet. It did 6700 RPM and 34 mph there.

This is all by GPS.

Altitude does indeed make a difference, even with a supercharger.

KH