Powerhead swap between 68 18hp, and 75 25 hp

Rwed

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jimmbo: what if i keep same carb on that 25hp head? keep it at 18hp?
 

Rwed

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Guy sent me pics of underneath of the ph. to check for scouring. how does it look?
 

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kbait

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I’d pass.. both cylinders have scoring.. you’re looking at a fair amount of work to swap to a marginal powerhead.
 

racerone

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He removed the exhaust cover on the side of the block.-----Run away-------See post # 10.
 

oldboat1

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So, why not work a little more on the one that's stuck. Tilt it up and fill the cylinders with ATF. Let it set for a couple of days, refilling as necessary -- see if you can get some movement.
 

Rwed

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yeah, the whole goal was to get a decent powerhead, to make a running motor as cheaply and efficiently as possible, this is the 3rd ph that's w good compression, but no count.
oldboat, do i need to remove the head before i start messing with it? or just work through plug holes?
 

racerone

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Remove bypass cover and inspect pistons and rings.------That will also allow you to fill crankcase with oil.
 

oldboat1

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Looks like someone was in process of working on the cyl head (one bolt partially removed) -- looks like the original gasket, but hard to tell. I would take it off, but take care particularly if a salt water motor. Run them in and out a little to make sure they don't break. With the head off, you can gently work on the pistons to free them up. Worth a try, anyway. Will be messy -- protect the floor.
 

Rwed

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Aug 16, 2018
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ok, so, this feller, went all out. and based on response from the J&E FB group, those pistons and cylinders look good.
I'm not here to question the experts.
Based on the photos i just posted... what do you guys think? he took head off to peer inside
 

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