On Sat, 28 Jun 2008 04:27:51 -0700 (PDT), Mark
wrote:

I'm seeing many older jet boats, say the 2000 sea-doo challenger 1800
or 2002 sea-doo islandia for sale locally. What are the fuel economy
on these older ones? Anyone know where you can find the information
out? Someone told me they get 5 hours on a tank, but I see the have
41gal tanks, so they are burning 8 gal/hour?

We have an example of the first jet boats sold in the US, a
turbocraft, SN 10. 1958 I seem to recall. Came with lifting eyes fore
and aft. You attached tow lines to the one and the anchor to the
other. Four clamshell vents at the gunnels. It came with a Graymarine
flathead six, 109 hp. My kid brother swapped in a Buick six that got
us 3700 RPM up from the 3200 we had been getting. Eighteen gallon
tank. Skiing it would go 3 hours or so. Neither engine was big enough
to drive the pump at rated engine speed and you can't change anything
out, like you can a prop or gearbox. So, many jet boats have a
mismatched drive train that may not be especially good for mileage. On
a small lake the actual top speed doesn't really matter much.

Casady