zero compression front cylinder 94XP

[smfabac]

We have a 94Xp (bought used 1999) that has
decided not to run over the 4th July holiday.

That was the first time we put it in the water
this year. It ran fine last year and was
winterized at the end of the season.

I pulled the plugs and tested comprssion:
145 rear and ten (10) on front . I pulled the
head and noted deep groves in cylinder wall
all around the bore. I expected to find broken
rings but when my son-in-law (professional
automechanic) pulled the boat home and
pulled the cylinder, he found the rings intact.

I have not yet viewed the piston and don't
know what it looks like. But the "water
ingestion" picture in your pulled pistons series
looks like the walls of the cylinder.

My son-in-law is reluctant to hang new parts
on the machine until he identifies the cause
of the damage.

Is it possible that I damaged the boat by using
the flushing adapter without a shutoff valve
at the end of the hose connected to the
flushing adapter (my uncle was maning the
shutoff at the faucet inside the basement and
may not have heard the command to turn
off the water before I killed the engine) .
After I shut off the engine and disconnected the
flushing hose, I fogged the engine by starting it
and allowing it to run as I sprayed the engine
fogging oil on to the flame arrester.

When we put the boat into the water the first
time this year, It started right up and my son
took it out but brought it back within 15 minutes.
He reported no problems with the boat, but when
my granddaughter tried to start it and take it
back out, it would not start.

I have two questions:

1) Given what I discribed above, is water ingestion
the likely cause of the damage or should we
look for other causes? I have never received
reports of the boat stopping when running at
WOT. However, I do recall that last season it
begin to lose speed and the rider would have
to back off on the gas and limp along for 10 to
15 seconds before he could resume speed.

2) If I replace piston, cylinder, and rings on
the front cylinder, should I also replace the
rings on the back cylinder (145# compression)?

3) If the front piston appears to be undamaged,
can I replace only the cylinder and rings, or is
that an unwise risk?

TIA Steve Fabac

[ September 21, 2002, 04:14 AM: Message edited by: smfabac ]

[John Kubiak]

For the price of the top end parts, and a little bit more, you can install a fresh SBT short block and add a lot of life back to your sea-doo.

The problem you describe sounds like several different issues, photos of the cylinder and piston would really help.

1994, 1995 and some 1996 models had a problem with the small oil injection hoses deteriorating from a chemical reaction with the paint that was used on the engines at the factory. That could possibly be the cause.

You may also have a fuel system blockage problem, and that will result in a similar failure.

[stumpy]

I have a 94 XP and it did exactly the same thing, meaning it would slow at WOT and when you backed off for a few seconds it would pick back up. It also only did that for a little while. A new SBT motor later, it ran fine for a while.....but that's another story :( . BTW, the little oil lines that John was talking about were broken on mine. Check them out. Anyway, I just replaced it and got it over with.