Bob, what model is your outdrive? Do you know the gear ratio? Seems to me
that you should be able to swing a more aggressively pitched prop (more
top-end speed) with that engine, but it would help to know your outdrive
specs.


"Bob" wrote in message
...
I am using a standard (aluminum?) 14x17 prop, which seems to match the
boat well because my WOT is about 5200 rpm, but than again I don't know
much about props. I do have a Sting Ray hydrofoil but I prefer not to
use it unless I am going to be carrying a large load...it surely helps
me get up on plane faster, but it also reduces my top end by a few mph
as well as making the steering feel "tight" and not as responsive as
without it. One thing that is different on my boat than many of the
newer boats, is that the bow is closed so I can't put passengers up
there, which probably does not affect the top speed, but sure does
impact the ability to plane quickly when the boat has more than a few
adults in it.


Stanley Barthfarkle wrote:
: What prop are you using? Do you have a Sting Ray Hydrofoil? If not, get
ne. Boat planes better, and it allows use of a higher pitched prop (14 X
21
:SS cupped in my case). Less cavitation, and no "rooster tail"- energy
that
:would have been wasted with a rooster tail is sent rearward, increasing
ropulsion.
:
:
:"Bob" wrote in message
...
: Dang, how do you get so much speed out of your little Volvo engine? I
: have a newly rebuilt AQ130C ( 4 cyl. 130 hp) and it only takes my boat
: up to 31 mph at WOT, about 5000 rpm with two adults in it. My boat is
: a 17' fiberglass v-hull and weighs about 2000 lbs I would guess, and
: has a Volvo 270 outdrive on it.
:
: BTW, it consumes just 3-4 gph at cruise speed (4200 rpm, 27 mph).
:
: Bob
:
: Stanley Barthfarkle wrote:
: :1985 Bayliner 1952 cuddy
: :18.5' fiberglass 'modified V' hull
: :19.5' Length over all
: :2200 lbs dry weight
: :1985 Volvo Penta AQ125B 4 cyl 105 hp 4 stroke
: :1 barrel Solex carb 35 mm
: :Volvo Penta 270 Stern drive
: :14 X 19 modified SS 3-blade prop (14 X 21 effective)
: :StingRay Hydrofoil
: :35 mph WOT @ 4800 RPM
: :32 mph cruise @ 4400 RPM
: :
: :Premium unleaded fuel (92 octane)
: :4 adults & 1 dog, ski equipment, coolers, etc-
: :6-7 gph WOT
: :5 gph cruise
: :
: :
: :
: :"Matt Lang" wrote in message
: . com...
: : Guys,
: :
: : I am thinking about getting a harbercraft jetboat ... these things
are
: : made from aluminum and have the 175 HP Mercury sportjet..
: :
: : 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... now I was
: : wondering how this compares to a similar sized fiberglass hboat with
: : 115-150 HP 4 Stroke outboard..
: :
: : What is the fuel you burn at cruise speed and WOT, whats your boat
: : size/weight and what motor are you running ..
: :
: : I am interested in how the relatively light alu jetboat compares to
a
: : more conventional boat with 4 stroke motor..
: :
: : Any info is appreciated
: :
: :
: : Matt
: :
: :
:
:
:
: