Fried engine

"Hey guys, Have a customer tha

"Hey guys, Have a customer that lost a serpentine belt on a Merc 5.7 TBI, 2001, MCM engine(Bravo3). He told me that he felt the loss of steering but shrugged it off and kept on truckin! About two miles later as he was pulling up to his canal, he got an alarm and idled her for maybe 500 yards and shut her down and coasted to a neighbors dock.

When I came over, I imediately saw that the belows had burned thru. The engine room was all sooted up. The engine did crank over and started up and I shut her down. The serpentine belt was laying in the bilge all shredded.

He assured me that he shut her off as soon as the alarm went off but by the look of the belows that had burned thru in a few places each, I am willing to bet he pushed her hot for longer than he said.

Relying on his assertion that he shut her off at the first sign of an alarm, I ordered belows, serp belt and installed only to start her up and find out that she is running poorly. I am pretty sure that there is significant engine damage.

My question is how long would he need to cruise her to burn up the belows??"

"with no water to cool the rub

"with no water to cool the rubber ,60seconds at power,
Do the basics and report back, compression ,spark plug inspection(melted/cracked ),leakdown test.oil contamination,"

"Oil is clear.

How can anyo

"Oil is clear.

How can anyone be so dumb as to run it in overheat. Alarm had to have come on earlier than he said....

OK, so 60 seconds to kill the belows, how long to damage the cylinders and pistons?"

"Is it fresh water cooled? Eve

"Is it fresh water cooled? Even without the raw water side running, it will continue to provide some cooling (still, much hotter than normal) until all the coolant is boiled off... which is probably what kept it running for as long as it did.
As far as the alarm goes, you might want to ask him specifically if there was any alarm going off, that he chose to ignore."

It is raw water cooled. He tol

It is raw water cooled. He told me he got an alarm right as he cut her down from a plane and then aparently motored an 1/8th of a mile or 500-700 yards. Then he shut her off.

I think those 500 yards did it...

If there is synthetic oil in t

If there is synthetic oil in the engine it might have been saved; see if the plugs are siezed. If they have a blue/purple tint on the outside it means they were tempered from extreme heat. Crank bearings may have melted and rings cracked along w/scored cylinder walls.

"Hi guys

Does any one about

"Hi guys

Does any one about how long the oil seal lasts on a mercury Alpha twe gen out drive,at the end of the prop shaft. Mine is good yet. I just want to know if it should be changed. As a matter of good OM

Thanks Jerry To do this my self, the tool is about 160.00"

"HI Guys
Does any one how lon

"HI Guys
Does any one how long the oil seal lasta on a mercury Alpha two gen outdrive. I have about 300 hrs on it . Every thing is in good shape. Just leave it alone or change.. The tool is about 160.00

Thanks Jerry New on the line. I do most of my own work. If i can help any , let me know . Thanks again.."

""Hi guys

Does any one

""Hi guys

Does any one about how long the oil seal lasts on a mercury Alpha twe gen out drive,at the end of the prop shaft. Mine is good yet. I just want to know if it should be changed. As a matter of good OM
Thanks Jerry To do this my self, the tool is about 160.00"

Gerald, I think you should start a thread on the subject. You will better have response that way.

On the other hand, It could be a flip of the coin. I usually change them as part of the maintenance protocol but recently, on a 4 stroke 225 Yamaha Outboard outdrive lower unit, I replaced seals on propshaft as a matter of regular maintenance and the drive started leaking after that. Upon disassembly, I discovered that the propshaft was grooved where the seal lip makes contact with the shaft. New seals would not seal up against the shaft and the shaft had to be replaced. Sometimes it is best to leave well enough alone. Pressure test it and change the gear lube paying attention for any milky oil. I would leave it but there are more experienced guys here that can better advise you and I am curious as to what they have to say.}"

""Sometimes it is best to

""Sometimes it is best to leave well enough alone."

Well said Bulit7.

If it ain't broke, don't fix it; especially a seal."