What to do with dead 2007 12Full

[cxp]

(Whoops, thread title should be "12F" not "12Full," stupid autocorrect)

A few weeks ago, a family member put our 2007 12F in the water for the first time this season. The engine apparently seized about 10 minutes later.

Before:

• Engine was running fine when winterized last year. Cooling system was winterized with RV anti-freeze. Oil was changed at the end of the season last year.
• Engine was running on the hose fine immediately before we put it in the water.
• Dip stick showed proper oil level before we put it in the water.
• Engine has about 350 to 400 hours. (I haven't checked recently.)

After:

• Engine won't crank at all, even with new battery.
• Dip stick showed extremely low oil level (lower than minimum).
• Bilge had about 5 gallons of oily water in it.
• Seemed to be a significant amount of oil near oil filter (but it could be leftover from prior oil change).
• Cluster reportedly did not report low oil pressure. (Told this second hand, so information not reliable.)
• Can't turn coupler by hand after removing plugs.

My best guess is that the oil filter was not tightened correctly, oil leaked out while running, engine lost lubrication and seized.

I hope to pull the engine in the next week.

Questions:

• Any other ideas on what could have happened and what to look for?
• How hard is it to pull the engine?
• Thoughts on swapping in a rebuilt engine from SBT?
• Are the SBT engines any good?
• How much work is involved in installing an SBT engine? It looks like I'd have to swap over the intake manifold, exhaust manifold, various sensors, etc. Is there anything difficult that your amateur mechanic couldn't handle?

Suggestions appreciated. I'm debating between (1) parting out the 12F and finding a replacement or (2) replacing the engine.

[steve45]

Could be the filter wasn't tight enough. Could be the wrong filter, or trash on the sealing surface.

If you can't turn the crank with the spark plugs removed, you've got big problems.

I wouldn't use an SBT engine--unless I was planning to sell it.

[ctct2118]

Cooling ports probably corroded and overheated. Seen it on them 12f & 15f alot.