Spun Bearing Cause

[TeamHoss]

I own a 2003 Centurion Cyclone (v-drive) with a mercruiser 350 MAG MPI (5.7). I have approximately 380 hours and do not drive the boat aggressively. I dropped the boat in the water in early June and was running back home to beat a storm. During the initial run I noticed the boat was starting to run rough and ultimately the engine stalled at which point I noticed smoke coming out of the engine compartment. Turns out my mechanic did not hook up all the hoses after witnerization and it fried the wet exhaust system. My mechanic owned up to the mistake and replaced all of the hoses. I dropped the boat back in the water in late June. I ran the boat for exactly one tank of gas. Literally after filling up I noticed a knocking in the engine as I accelerated and that knocking continued to get louder the faster I went. I pulled the boat out of the water and brought back to my mechanic. He tells me I "spun a bearing" and that he reccomends a rebuilt replacement motor.

I asked if the spun bearing was related to the overheat issue and he said "no they are independent issues". I am not a mechanic, but I have to beleive that the overheat may have caused this or be related to this issue. Thoughts?

[tazmann]

Tuff situation but Yes that is one of the things that happens from over heating.
With only 380 hours that should not have happend under normal use unless it was run low or out of oil.
Tom

[Frosty]

What were you doing when you heard it knocking. It a close call but a spun bearing will be from a good thrashing of a cold engine. Overheat is the top end but as I say its a close call.

[PAR]

An examination of the bearing (very likely the #1 rod) will tell all. Your mechanic may be looking for a way out, but I'll bet his insurance company has a different reply when faced with the realities of the damage claim.

[gonzo]

That is a likely result of a severe overheat. However, he can argue that you are responsible for keeping an eye on the gauges and turning off the engine if it overheats.

[Frosty]

If it spun from overheat that block will need line boring and head facing along with heads of course, new pistons bearings etc.

Buy a new short motor,-- a good guy will swop that in a day.

Put an Edelbrock manifold on it while you are doing it , the best bang for bucks ever.

[gonzo]

A remanufactured engine (long block) with 18 month warranty is $2600.00 at your door.

[Frosty]

Thats cheap--are you sure?

[gonzo]

That's what I sell them for.

[Frosty]

America --hot rod heaven.

[Landlubber]

...geez Gonzo, that is unbelievable compared to our prices here too....wish we could buy here so cheap, no wonder there are so many fast cars there....