Probably not the same thing but mine had a loud clattering sound the last time out as well. It turned out a screw that holds the cover on the electric trim motor came loose and the cover made a clatter sound. Put my hand on the cover and the sound went away. The clattering sound was very concerning and I was glad it was something simple.


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Had something similar happen as well, nothing at idle, nothing on the trailer, sounded like an exhaust leak, mine was the number 7 rod bearing though, got hot and spun but didn't demolish itself so the sound wasn't what I expected


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That's kinda what I'm thinking to guess I won't for sure now till I pull motor 2 season ago I spun cylinder 8's rod bearing  but couldn't hear it at a idle but was able to hear it when I left off the throttle it give a couple wrap sounds and then settle down  thank for the info guys


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Did they kinda look like this



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There journal looks ok I think I misuse caught it in time



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That's gotta come apart..... All the way down.

Yeah just not sure where I went wrong my clearances were all in spec I got maybe 10 hours on these bearings and crank


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The ten questions;

What oil?

What oil filter?

What oil pan?

What block?

What where the rod clearances?

What were the main clearances?

What bearings?

How many RPM max?

Is it just the rods, or do the mains look like crap too?

Any idea what oil temp?




GT

Mobil 1 full synthetic 10-30

Bosch filter I usually run a Delco pf454

Oil pan I'm not sure of it was the one that came with my motor already in the boat holds about 7 quarts

It's a hi perf passenger block 2bolt main I looked up the casting numbers and it came up as 2bolt or 4 bolt is a 78 I'd have to look it up again it's been awhile

My clearances I wrote them down I'll have to go back through my stuff I platigadged them and I remember there where dead on

Bearings where clevite

Rpms 4-4500 max never for long

And I'm going to pull the rest of the caps and mains tomorrow.  I seen this and called it a night


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Mobil 1 full synthetic 10-30

Sure seems light.

Bosch filter I usually run a Delco pf454

Both seem OK....Try a WIX Racing or NAPA Gold... Cheap and a quality filter. That don't happen often..

Oil pan I'm not sure of it was the one that came with my motor already in the boat holds about 7 quarts

A picture would be awesome.

It's a hi perf passenger block 2bolt main I looked up the casting numbers and it came up as 2bolt or 4 bolt is a 78 I'd have to look it up again it's been awhile

So no weird oil porting.... Should be good...

My clearances I wrote them down I'll have to go back through my stuff I platigadged them and I remember there where dead on

Plastigauge is somewhat useless... JMO

Bearings where clevite

Any idea what series?

Rpms 4-4500 max never for long

And I'm going to pull the rest of the caps and mains tomorrow.  I seen this and called it a night


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Cool.


GT

Did they kinda look like this



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Gawdamn... that ain't too purdy. The crank journal... might be the pic... but what's going on with the surface finish? Was it like that on assembly? Bearings kinda giving signs of either poor lubracation gone to far... or some clearance issue. Was that 38-40 oil psi at idle? Wot? Cold temp? Operating temp? And what sort of clearance were you seeing on the rods? Well... mains as well?


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