On 18 May 2004 08:22:34 -0700, (Matt Lang) wrote:
I am thinking about getting a harbercraft jetboat ... these things are
made from aluminum and have the 175 HP Mercury sportjet..

A good rule of thumb for estimating fuel burn is 1 gallon per hour for
every 10 horsepower. Actual horsepower at cruising speed should be
about 50 to 60% of maximum. Using those numbers you get a fuel
consumption of 9 to 10 gph which sounds about right to me.


So far so good ... Now what raises the fuel warning flag are the
terms:

- jet
- 2 stroke
- carburator (two of them

The boat will burn about 5 gallons per hour at 30 mph...

I don't think so, see above.

By way of example I have a 24 ft I/O with a 350 cid Chevy rated at 260
hp. At cruising speed it burns about 13 gallons per hour.

My former Bertram 33 had a pair of 454 cid Chevys rated at 350 hp
each. At cruising speed it burned 35 to 40 gph.

My 15 hp Merc 2 stroke burns about 1 gph.

My 15 hp Merc 2 stroke burns about 1 gph.


I have been tracking my fuel for about 200 hours. I am doing a tad over 1 GPH
on a 20' pontoon with a 60 merc 4 stroke but I don't go fast very often. I
cruise at around 3000rpm

"Wayne.B" wrote in message
...
On 18 May 2004 08:22:34 -0700, (Matt Lang) wrote:
I am thinking about getting a harbercraft jetboat ... these things are
made from aluminum and have the 175 HP Mercury sportjet..

A good rule of thumb for estimating fuel burn is 1 gallon per hour for
every 10 horsepower. Actual horsepower at cruising speed should be
about 50 to 60% of maximum. Using those numbers you get a fuel
consumption of 9 to 10 gph which sounds about right to me.

Nasty. The 180 hp Cessna I fly burns 7.5 gallons per hour and cruises at
130 knots.

-c