HP500 EXCESSIVE FUEL USE IN 28' DECKBOAT

[Outofgas]

HEY GUYS, NEW HERE AND I'M LOOKING FOR SOME FEEDBACK. I HAVE A NEW 28' MAGIG DECKBOAT, 12HRS,
WITH THE HP500, XR DRIVE, ALL THE GOODIES.
WE ARE BURNING THROUGH THE PETROL!!!!?
WE BURN A FULL TANK, ONE SIDE, FROM BRIDGE TO DAM AND BACK:JUST CRUISING @ 4000 RPM.WE ARE NOT OVERLOADED; FOUR ADULTS, A PAIR OF KIDS.
LOOKING FOR HELP? WHEN I RE-FILL THE TANK, I CAN ONLY GET 20 GALLONS MAX INTO THE EMPTY TANK.
FRUSTRATED!

[Keith E. Sayre]

Something isn't right. Take it back and have
Mark or Clue check the overflow hose to the tank
to make sure that it's working right. You could
have a pressure problem if it isn't bleeding the
air properly as the gas is filling it up? That
same problem could create suction when draining
the tank and could stop the flow of gas to the
motor which could make you think it was empty?
That's one possibility? Good luck. FYI--the HP500 won't use too much more gas in a day than
the 496 packages would. Good luck.
Keith Sayre
Conquest Boats
Lake Havasu City
928-680-1400

[mike37]

HP500 gas hog
496 ho not a gas hog

[Jrocket]

I've got an HP500 in my Mach26 and it does ok on gas,especially for the way I drive. You also have alot of boat there(28foot).How much trim are you running at those rpm's? Is the boat packing air under it or plowing the water?

[riverliver]

Outofgas:
WHEN I RE-FILL THE TANK, I CAN ONLY GET 20 GALLONS MAX INTO THE EMPTY TANK.
FRUSTRATED! May be the tank is not empty and it is reading empty.
Iam runnins a blown 502 with 2 850s 0n top of a 871 and can run from havasu springs to topoc and back on a 1/2 tank or so if iam not running to hard.

[Trash]

As a reference mark, you should be getting about 2-2.5 mpg at that rpm with that motor. Like Keith said, check the tanks, then get a GPS and run a certain distance with a topped off tank, fill it up again, note distance and calculate mileage. I usually get around 3 mpg with a 350 Mag/EFI MP in a 21' that weighs around 3800-4000 lbs loaded. BTW that's at 3000 rpm.

[Sandbar Mike]

My 29 cat w/540ci will run from the London Bridge to Havasu Spring and back on half of one of the tanks, I guess that means about 22.5 Gallons.
Thats at 4600rpm @ low 70's mph
I'll bet you have a bad sending unit in one of the tanks,
2cents

[OC-PARTYCAT]

I have the same problem with my partycat. The guage is reading empty but only about 20 gallons will go in. The problem is, the tank is only half empty (or full) . The sender in the tank isnt long enough.

[Keith E. Sayre]

OC-Partycat just made a valid point. Most deckboats have very long and thin gas tanks
which makes it difficult for the senders to
measure the gas accurately. A half inch
vertically is alot of gas yet doesn't change
much at the senders position.
Keith Sayre
Conquest Boats
Lake Havasu City
928-680-1400

[MKE - POWER]

OUTOFGAS is a friend of mine. His problem is that he is actually running out of gas, no more go.
It has happened three time on the lake, and last
week when he was putting it on the trailer.
He has only been able to fill it with 20 gals.
I don't mean to to step on his post, but I don't know if he has been in town recently.
Anyway, we think that maybe they put smaller tanks
in by accicent, or therre is a pick-up problem.
We talked to the salesman at the L.A. show, and he wasn't sure of the tank sizes, maybe 25 a side.