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Discussion Starter · #1 ·
I bought a used 1992 Seadoo GtX with 587. I redid topend rebuilt Carbs, one piston/rings was bad, cylinders were bored 50 over, will I need to adjust the timing? Also I tested oil injection pump with a drill and it appears to be working should I check anything else given blown cylinder?
 

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It is easier to look at the piston skirts to tell what happened. But the
Water damage is obvious in the cylinder picture.

Looks like water damaged piston(s) that seized, restarted, probably
seized a few more times. The last seizure may have have been
preignition, or a poor quality piston breaking.

Causes: Missing gray drive line (pto) cover, oem flame arrestor is
missing, hull takes on water faster than it bilges, the bilges are not
functioning properly.

Basically water is going into the carbs while the engine is running.

Future problems: The RV cover clearance was damaged by the
water ingestion too, the main seals most likely need to be replaced,
Both problems will lead to hard starting and other carb related
problems.


Bill M.

But if a fuel primer was installed before you bought it, than it
most likely had hard starting and carb problems that were
(possibly) never fixed.
 

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Discussion Starter · #7 ·
It is easier to look at the piston skirts to tell what happened. But the
Water damage is obvious in the cylinder picture.

Looks like water damaged piston(s) that seized, restarted, probably
seized a few more times. The last seizure may have have been
preignition, or a poor quality piston breaking.

Causes: Missing gray drive line (pto) cover, oem flame arrestor is
missing, hull takes on water faster than it bilges, the bilges are not
functioning properly.

Basically water is going into the carbs while the engine is running.

Future problems: The RV cover clearance was damaged by the
water ingestion too, the main seals most likely need to be replaced,
Both problems will lead to hard starting and other carb related
problems.


Bill M.

But if a fuel primer was installed before you bought it, than it
most likely had hard starting and carb problems that were
(possibly) never fixed.
Thanks Bill, what indicates the water damage? Spark arrestor and stock intake was all installed when I bought it, no indication of flooding in the hull. water lines all connected.
The last seizure may have have been
preignition, or a poor quality piston breaking.
The last seizure may have have been
preignition, or a poor quality piston breaking.
Thanks, it doesn't appear that the engine had never been rebuilt, all original clamps,
 

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Those pistons in your pictures were not stock Sea Doo pistons.

Look at all the vertical lines in the cylinder. Each of those lines
were caused by a water droplet. The same thing happens to
snowmobiles when they ingest snow.

Water damage causes more damage to the pistons, than the
cylinders.

The water has a couple other sources. From the exhaust, when
you crash and roll the ski upside down, or from a leaking base
or exhaust gasket.

When you assemble the engine, use the exhaust manifold as
a jig (without the exh port gaskets) to align the cylinders before
you torque the cylinder base gaskets.

Keep in mind, if the water came through the intake, the RV
clearance should be inspected.

oetiker clamps are cheap, easy to remove and install. IMO they
are significantly better than regular hose clamps, and part of
a pro rebuild.


Bill M.
 

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Discussion Starter · #9 ·
Those pistons in your pictures were not stock Sea Doo pistons.

Look at all the vertical lines in the cylinder. Each of those lines
were caused by a water droplet. The same thing happens to
snowmobiles when they ingest snow.

Water damage causes more damage to the pistons, than the
cylinders.

The water has a couple other sources. From the exhaust, when
you crash and roll the ski upside down, or from a leaking base
or exhaust gasket.

When you assemble the engine, use the exhaust manifold as
a jig (without the exh port gaskets) to align the cylinders before
you torque the cylinder base gaskets.

Keep in mind, if the water came through the intake, the RV
clearance should be inspected.

oetiker clamps are cheap, easy to remove and install. IMO they
are significantly better than regular hose clamps, and part of
a pro rebuild.


Bill M.
I did use the manifold as a jig to install the cylinders as you indicated saw it on a video as well. There are some grooves on RV cover but not on engine side. Does the timing specs change with bored cylinders?
 

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The groves should only be on the intake side of the RV and the
RV cover.

They were caused by water coming through the intake. But your
cylinder had water marks everywhere, so like I mentioned, some of
the water may have came from the exhaust.

Bill M.
 

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No,

some of the water obviously came through the carb. But it did not
cause significant damage to the RV cover, and it will not cause
starting or tuning problems in the future.


Yrs ago, we used to have a problem stripping threads on the upper
2 RV cover mounting bolts if we got our bolts mixed up. So during
assembly make sure the upper 2 bolts are not longer than the ones
you removed. A longer bolt will bottom out against the cylinder and
strip out the threads.


Bill M.
 
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