pump replacement

['97 Scarab Jet]

After looking back at some of the older post, it appears that my Volvo PJX pump in my SCARAB has some internal flaws that hinder the boats performance.
So the question, can I just change out the whole pump and replace it with another/better pump?
I realize that the hull cut out would probably differ, which leads me to the next question.
Would it be possible to do some fiberglass work on the hull (probably fill in the gaps or whatever) and still keep its strength/integeratity?
FYI, this would most likely be done along with an engine upgrade.
Just curious,
Joe

[rivercrazy]

All of what you are asking can be done. It will be pretty expensive though. If your serious, I would recommend either a Dominator, American Turbine, or a Legend pump to replace it.

[jacuzer]

Saw on your earlier post that the Volvo jet is maybe a Legend?
If so, contact them and see what they say.
www.legendjet.com (http://www.legendjet.com)
What design is this PJX pump?
Is it closer to the G pump or E pump?(See legend website)
I'm thinking of the only Scarab jet I've ever seen, the LA boat show a few years back and all I thought to notice at the time was that it was a Volvo jet. Is yours the boat with a fold-over ladder that kind of picks up the lines of the boat?
If this is the style, I would say you are going to be challenged with changing out the jet. If I remeber correctly the boat interior was styled around the engine/drive.
Can you post a picture of your boat to give us more to ponder?
Kevin

[Scarabjet]

Joe,
The front part of the PJX differs from all other pumps and you will have to spend some $$$ to have the hull modified to accomodate a different pump.It can be done & it's just a matter of how deep you're willing to dig in your wallet.
The bowl, impeller & nozzle is all Legend. Call Dave @ Legend if you'd like first hand knowledge on its history. I talked to him extensively when I was researching the PJX and trying to determine the best impeller cut to use in my particular application.
One of the problems in design of the PJX is its long suction piece, causing that "lag time" you may have noticed on hole shot (coupled with the torque curve of the V6...). Yours is probably quicker than mine because you're using a B-Cut vs. my C-cut.
Rick

[Mike J.]

A Brief History of the Scarab Jet Boat.
The Scarab Jet Pump was designed by Team
Scarab in Calif. By Warren R. and a group
of X Designers from Berkeley/Legend.
The Design was for a 4cyl Inline Mercury
GM Motor.
The design was close to the E pump in
size but had a number of NEW features.
The intake was different and the Bowl &
Impeller were smaller.
The Scarab Jet Sprint was designed as a
less than 16ft Bow to transom with a Swim
Step made it overall 17&1/2ft.
The first Boat was made from Chalk drawings on the floor at the shop in Ventura Calif.
I Still Own that 1st 16ft Boat.......
My Boat is the only one that has a cutout
in the Swim step that we used to test a
Outboard Motor.
I made a Adapter from the Scarab Intake to a Legend Bowl and Impeller, Still have
the adapter on my Boat, It worked well
and allowed me to increase HP and top speed.
The unit was then redesigned and sold to
Volvo.
The Boat (Mine) was sent to Wellcraft for
Testing, Their Engineering Group/Sales
did not think there was a Market for Jet
Boats, But Volvo owns 20% of Ganmar who
owns Wellcraft SOOOO a 181/2ft Long and
Wider/Heavied Boat was designed at Wellcraft with the Volvo Pump.
The 1st Boat (Mine) can be seen at
www.cinemarentals.com (http://www.cinemarentals.com) "Reel Boats"
Scarab Cam 14l.jpg.
I have contacted DON at ADM Boat Works
and He will be able to help anyone who
has Questions or needs Parts.
Mike J.
Legend

[Mike J.]

Sorry: The Bottom of my post was cutoff
and the word LEGEND is under my name, I
have NO connection to Legend and only
tried to include phone Numbers and people
to contact.
Mike J.
Legend Jet Drives 510-215-8456 DAVE
ADM Boat Works 714-898-8447 Don

[Scarabjet]

Mike,
Thanks for posting with the background. I did not "volunteer" you because it wasn't my place to do so. Glad you got involved.
Rick

[Slick]

I'm not knocking your boat or your dream for speed. However, I'd take a serious look at what that's going to cost. I'd imagine you'd be alot further ahead if you started with a different boat with an existing big block and an AggreLegenBerkelDom pump. :D
Slick
[ December 06, 2002, 02:43 PM: Message edited by: Slick ]