Oops

[Guppy]

I diagnosed a horrendous engine noise as a blown lower unit… WRONG !

Here’s the story…..

bought a brand new OEM lower unit, bolted on,,, same freaken noise…. Grrrrrrr

finally got a Mobil mechanic to stop by, puts the muffs on , starts er up,,, sounds like garbage disposal with silverware in it… increased rpm lessons the noise…
with the engine in the water in gear same horrendous noise..

here’s the punch line,,, he pulls the plastic shroud off that covers the fly wheel and timing belt,,, low and behold the fly wheel nut is sitting on top of the fly wheel at the edge of the wheel…. puts the nut back on torque it down,,, NO MORE FREAKEN NOISE !

5 weeks, $1800 lower unit and countless hrs looking for the cause of that ungodly racket, it’s a loose nut…

best I can figure at low rpm it really jumped around and made the most noise,,, at higher rpm centrifugal force kept it forced out to the edge with less noise… the nut hitting the shroud made one sound and when hitting the fly wheel it resonated down the drive shaft and made it sound like lower unit failure!

I hate to admit it but I’m the yahoo who changed the timing belt a couple yrs ago and evidently didn’t torque the nut enough… Dah!

if nothing else I saved some money not burning any fuel….. for sale: 68V-45300-34-8B lower unit….
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Thanks, Gup
God Bless America