Mettyfish's 15hp powerhead

bktheking

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I got it today, to refresh everyone's memory this was the 15 with low compression on one cylinder, he pulled the head and found scoring.

The top piston is scored badly, the bottom one seems fine. The reed for the top piston has a slight gap so it will need to be replaced. It's an early powerhead with the thermostat on the bottom of the head, CD motor. The other observation I made is that someone had been in the powerhead prior. Gaskets have been changed, the screen on the reed plate wasn't on anymore, it was just sitting on the plate and dented. The crosshatch pattern on the cylinders wasn't a good one, someone had tried to hone it. The sides of BOTH rods were scored , almost as if someone had honed the cylinder too much and put the same standard pistons in causing the rods to shift and rub the crank. Reeds wouldn't cause this, it's mechanical in my mind. Anyone have any opinion on these observations?

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Bearing are all there, none missing. Crank journals are NOT scored either. Clips in the pistons wrist pins are all in tact. Nothing else missing, it just doesn't add up. Score marks on the rods and top cylinder scored, all I can think is that the metal from the rods ended up in along side the top piston. Rings are not broken either. If a bore job and pistons are doable, are the rods worth reusing?
 

1946Zephyr

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Re: Mettyfish's 15hp powerhead

Is this the one that had the little chunk gone from the head?
 

bktheking

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Re: Mettyfish's 15hp powerhead

No, that one was fixed with a head replacement.
 

1946Zephyr

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Re: Mettyfish's 15hp powerhead

Oh, okay. My bad.:D

Those pistons........:eek::eek: Looks like a slight overheat problem huh? I rebuilt a 35 that had pistons like that and it was due to a waterpump failure.

Is that deadblow on your bench for driving the piston out?:D
 

bktheking

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Re: Mettyfish's 15hp powerhead

No I was using it to seperate the crankcase, pistons - pushed them out by hand. Still doesn't explain why the side of the conn rods are scored, both rods - not just the bad piston.
 
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