Resurrected 2005 Seadoo 3D 787 RFI Low running hours Plug Fouling? EDIT: METAL CHUNKS IN CYL!

[evofxdwg]

EDIT: NEVER MIND ALL THIS, JUST SKIP TO THE NEXT 2 POSTS. BAD NEWS. REBUILD TIME I GUESS.
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Purchased from a dealer “new old stock” on Ebay for a lowball bid in 2007.
Probably run not more than 25hrs around 2008-2009 - ran fine then. I had it up to 70mph with my fat ass on it.

Family member used it and wrapped rope around output shaft and bent it.

Winterized and put up. Ended up sitting in shed over 10 yrs. Then grandson wanted to get it running.

MAINTENANCE HISTORY: There has never been any motor or attachment disassembly adjustment of timing, oil injector, valve service, etc. It is like it was from the factory.

(winter/spring 2022):
Fixed shaft with new one (purchased many years ago and stored), replaced carrier bearing, carbon ring seal, etc. (jet pump was OK)
Since it had been sitting, we:
-Cleaned out fuel tank, hose.
-Rebuilt fuel pump module with new (Quantum HFP-382-SDT) pump motor, filters
-Plugs were removed and inspected but re-used.
-Replaced battery (Deka AGM ETX16L), charged it on maintainer for days
-Replaced starter solenoid (twice - those things are junk)
-Replaced oil tank output filter
-Put in fresh gas (premium)
Started in driveway, with garden hose cooling, ran it 10 minutes or so. Smoked a bit but It had been well fogged before putting it away 10 yrs earlier

Took to lake ($11 FEE):
- ran 30 minutes, including a few short high speed runs.
- Started running rough. Came back to dock, wouldn’t start again.
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Back to garage:

• Removed fuel rail and injectors:
• Put Kroil in injectors and let them sit 3 days.
• Ohmmeter reading 2.8-2.9 ohms on both injectors. Applying 12V caused the audible click.
• Injectors didnt look fouled or dirty, but the screens might have had some crud on them, blew it out with compressed air as well as possible

- Removed plugs: One (I think rear) plug was very oily, other moderately
- Got a fuel pump pressure gauge and installed a T fitting with port:
- fuel pressure is running 55-60psi as soon as key installed. So assume the new pump is good)
- pulled plugs out and grounded them with a clamp and wire and observed both were sparking
—————-
Today:
-Gapped and Installed new NGK BR8ES plugs
- Started in driveway, with garden hose. RAN for 25 minutes or so, including blipping the throttle several times. Everything seemed ok.

Took to lake ($11 FEE).
-WOULD NOT START AT DOCK. ONLY A FEW SPUTTERS.
- Removed plugs at lake. Again, one quite oily, the other moderately so.
CUSS WORDS!

Came home, wouldn’t start in driveway

• Removed the new plugs and cleaned with gasoline and dried with compressed air. One looks white/shiny like it came out of the box. The other (rear plug), has oil staining that gas will not rinse off.
• Reinstalled the cleaned plugs, a bit more sputtering, but would not start.

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Im assuming weak or no spark possibly aggravated, or maybe fully caused, by oil fouling, which might be particularly susceptible due to the very narrow plug gap.

Note nothing else ignition related has been replaced. (Plug wires, magneto/coil, electronics module, etc. are original).
Grandson wants to take it on vacation in a couple of days.
I have the 3D vehicle shop manual and engine shop manual. But thought some of you might know the most likely path of success.

WHAT IS MY NEXT STEP?

Take to the nearby service center? (I know it won’t be ready in a couple of days in that case). Can they still work on these old ones?
I have read they are very susceptible to low battery voltage. I will charge up fully and try to start again while monitoring voltage.

 

[evofxdwg]

UPDATE:
We ran a compression test.
Front: ZERO
Rear: 90psi after about 3 seconds cranking

maybe a reason we observed: The front plug is the cleaner one.

So obviously a front valve stuck open and rear compression not in spec either. (Grandson says 150psi desired)

Im at a loss for how it even started and ran for 20 minutes the other day ????
Grandson had never driven it so not a good judge if it ran OK, enough power, etc. I did not drive it.

Off to look in the book on valves.

 

[evofxdwg]

Further UPDATE:
I remembered I have an inspection camera so put it to good use.
These are all the front cylinder. That chunk of metal is embedded in the underside of the head. And there are lots of gouges in the head in other places. Is that chunk of metal part of a piston ring or skirt? I cant tell for sure but looks like the edge of the piston is broken off. Walls do have some vertical scuffs.

 

[evofxdwg]

As I said, im at a loss for how it started and ran the other day at the lake, unless this all happened at the end of that 20 minutes. And I don't understand how it would happen on a motor with very low hours, even if it had been sitting 10+ years. I guess my grandson is going to learn to rebuild a Rotax.

Any tips for the rebuild? Stuff to do while we are in it. Kits available?

 

[mikidymac]

First off, you should never run it more than a few minutes even connected to the hose because you will burn up the driveshaft seal let alone 10-25 minutes.

If one plug was white then you aren't getting enough fuel and oil and it is running lean.

With that much metal in the engine you need to take it completely down and inspect the rotary valve and crank bearings.

WSM makes good stock rebuild kits and Group K can bore your cylinders.

 

[etemplet]

I don't often advocate replacing the crankshaft or any parts as I repair/replace items based on condition.. With the amount of metal in the photo I'd say it is very likely that metal got where it shouldn't be. Unfortunately there is no way to remove it without pulling the crank apart rebuilding or replacing. Good Luck !!