Sea-Doo RPM drop question

[cio...@my-deja.com]

A few weeks ago I was riding my 97 SPX and noticed a drop of
approximately 500 RPM or so. I assumed it was carburetion problems
since I was dinking around with the low/high and idle settings to try
to dial it in. Anyway once I started losing the RPM I packed it up for
another day.

Yesterday I went out to test one final time, tiny tach in hand before I
would make the decision to take it to Watercraft Magic (where I know it
would be fixed) or attempt to troubleshoot it myself. I rode it around
and was turning about 6800 RPM. A bit low from the 7000 (Factory spec
1) figure I once had about six months ago.

Despite a few hundred RPM drop the ski did run good for about 30
minutes. Then the RPM went down to about 6200. When I hit the shore to
look inside the engine compartment, the pipe chamber body was white
(salt deposits on a hot pipe).
The chamber body was hot enough to sizzle water. Now I knew something
was really wrong. The chamber body normally gets hot enough to want to
take your hand away after holding it on there for five seconds but it
never sizzled water.

I pulled it out of the water and verified that all the cooling lines
were clear, they were. The cylinder, cylinder head and head pipe were
normal temperature. Only the pipe chamber body was hot. This made me
look at the waterbox regulator since it seems to be the only source of
water for the chamber body.

When I opened it, a bunch of water pored from it. The diaphragm came
unseated. I reseated it and blew into the regulator verifying the
normal up and down movement and it seemed to be seated well.
Reinstalled it and hit the water. 6900 RPM, still a bit low but the
speed was back……..for about 15 minutes…..then back down to 6500 RPM. I
popped open the regulator and the diaphragm was unseated again.

When I reinstalled the diaphragm it seemed to be in nice and tight. It
takes quite a bit of force by hand to pop it out.

1) Is it just worn out?

2) How much pressure should it be able to handle before it unseats?

3) Could something else within the system be causing excess pressure
build up in the waterbax causing it to unseat?

I am just asking these questions before I drop $100.00 on a new
regulator.

Sent via Deja.com
http://www.deja.com/

[Carolina Watercraft Works, Inc.]

You might want to try and richen up your carbs a tad. Cooler
temps require slightly more fuel. A slight lean condition will
reveal itself with lower RPMs at first. Sounds like you are close,
but a little more fuel may take care of it. Bear in mind that the
hotter than normal water temps in your motor (due to a lean
condition) will cause things to expand and loosen up, which may
be causing your diaphragm to work loose.
--
Laszlo Almasi
Carolina Watercraft Works, Inc.
2104 Langdon Road
Raleigh, NC 27604

<cio...@my-deja.com> wrote in message news:91iqjj$uk1$1...@nnrp1.deja.com...

> speed was back....for about 15 minutes...then back down to 6500 RPM. I

[Bill O'Neal]

Lazslo,
He is talking about the diaphram on top of the waterbox. It should never get
hot with the cool water from the pump going in and out of it.

He may need to use a thin tie-wrap around the base of his diaphram to secure
it to the regulator body to keep it from coming off.

Some guys just eliminate the regulator alltogether and use hard jetting in
the pipe and in the waterbox. 120 pipe, 140 waterbox, and a plastic tee.

Bill O'Neal
WCM
Carolina Watercraft Works, Inc. wrote in message
<91irvm$vua$1...@nntp9.atl.mindspring.net>...

[Carolina Watercraft Works, Inc.]

I agree, but don't couldn't it be possible that the steam
created in the pipe jacket could work it's way back down
to the waterbox valve causing the expansion? There should
a clamp at the small end of the diaphram and a clamp at the
big end. And he stated the pipe itself was hot, not the water
box. Something is causing the pipe to get hot. It's either
a blockage, or it's too lean.

BTW ciocca, the majority of the water for the pipe is supplied
via the engine, through the exhaust manifold and into the top of
the head pipe.

--
Laszlo Almasi
Carolina Watercraft Works, Inc.
2104 Langdon Road
Raleigh, NC 27604

"Bill O'Neal" <water...@worldnet.att.net> wrote in message
news:6G6%5.2655$GQ1.1...@bgtnsc06-news.ops.worldnet.att.net...

[cio...@my-deja.com]

You might want to try and richen up your carbs a tad. Cooler
> temps require slightly more fuel.

I have the plugs with a nice brown color doing my high spped kill the
throttle runs. The RPM only drop when that damb regulator diaphragm
pops loose. Aslo only the "Chamber Body" got hot. The head, cyclinder
case, and head pipe were normal temp. The only water the chamber body
sees is from the regulator??? correct??? By the way Bill recommended a
tie wrap??? Isn't the plastic of the regulator too hard to compress
with a tie wrap?

In article <91irvm$vua$1...@nntp9.atl.mindspring.net>,

[Carolina Watercraft Works, Inc.]

Ok, I thought you meant the pipe itself was getting hot.

In that case, I would look closer at your diaphragm like
you were. There is supposed to be a clamp on both ends
of the diaphragm to help keep it on. If they are gone, a tie
wrap, like Bill mentioned, should suffice.

--
Laszlo Almasi
Carolina Watercraft Works, Inc.
2104 Langdon Road
Raleigh, NC 27604

<cio...@my-deja.com> wrote in message news:91j5vc$6te$1...@nnrp1.deja.com...

[CDPCB]

you might want to go ahead and just hard jet system like bill said ,allso
install inline filters
chip d. pcb

[cio...@my-deja.com]

Laszlo,
The round plastic piece (at the bottom of the inside) that snaps into
the regulator (the one with the two small holes) is what is unseating.
It is attached to the actual diaphragm that I bilieve you are talking
about (that has the clamp). If that part is worn out, I will just
replace the assembly vs messing around testing with a bunch of sub
components. I just want to know if the waterbox due to some defect is
capable of super high pressures that could cause it to unseat.

As far as hard jetting is concerned, won't that pull down peak RPM
since water will always be injected into the chamber body vs being
cutoff by the regulator?

In article <91j9oj$qg1$1...@slb2.atl.mindspring.net>,

"Carolina Watercraft Works, Inc." <loba...@mindspring.com> wrote:

[Bill O'Neal]

The problem is not the diaphram, it is the piece below the diaphram. It
keeps poping out of it's seat, shutting off all water to the chamber of the
pipe.
Either hard jet it or replace the water regulator.

Lazslo, the water is injected into the inner pipe from the regulator, steam
from the water jackets has no way to travel back through the tube to the
regulator.

He is asking if it is possible for backpressures from the waterbox to cause
his regulator to unseat itself. I think he needs to squeeze the hose from
the WB to the outlet to see if it has delaminated, blocking his exhaust. I
have seen hoses that look fine, but when you actually feel them, they feel
soft and delaminated to the piont that they will block the exhaust system.
Shaking the muffler for rattling metal is a sure sign of a broken baffel,
which can be a sourse of blockage too.

Bill O'Neal
WCM
Carolina Watercraft Works, Inc. wrote in message

<91j9oj$qg1$1...@slb2.atl.mindspring.net>...

[Carolina Watercraft Works, Inc.]

You are right about the hoses. The Kawi 650 used to be
very susceptible to that. I even diagnosed that very same
thing to Andrew (Able2ski) a while back and just replaced
one on an XPL in right now. Didn't think about it at first, but
now that you mention it, that sounds very much like what he
may be experiencing.

But water is also supplied to the pipe via the exhaust manifold.

--
Laszlo Almasi
Carolina Watercraft Works, Inc.
2104 Langdon Road
Raleigh, NC 27604

"Bill O'Neal" <water...@worldnet.att.net> wrote in message

news:J9d%5.2110$JH3.1...@bgtnsc07-news.ops.worldnet.att.net...

[SEADOOJJ]

take off that piece of crap water regulator and just hard jet everything. I
hate that regulator. My ski never ran better till I took off that POS and just
hard jetted the pipe.