Boatsnhoes
Contributing Member
The good news is I've (we've) sorted out quite a few problems, and now the motor runs pretty well. Water is flowing through it, and all in all everything above the exhaust hole looks good.
Bad news is this means I have to start thinking about the lower unit, crankshaft, etc.
So I have a few questions before I get started.
1) I stuck a borescope up the lower unit to get a look at the drive gear. It looked pretty darn rusty. Not irrecoverably so, and I'm pretty sure the crankshaft would still engage, but it's worrisome. Is this normal? Do I need to replace it, and if I do have to replace it, how difficult/time consuming is that? I was really hoping to keep the powerhead mounted and un-split, so hopefully that's avoidable.
2) I got a lower unit as part of the deal for the motor, but I'm not really clear on what's missing. It appears as though I'm missing parts 27-33 and part 3 of the shift shaft. What am i missing from the prop side, though? What you see in the pictures below is everything I have. Mostly I'm trying to match a part number to that exposed piece with 4 open screw holes on it, so I can tell what numbers above it I need.
Part numbers I'm referencing are here: https://www.marineengine.com/parts/...rts/mark-35a/all/gear-housing-assembly-page-1
3) The lower unit sounds very...crunchy when i spin the crankshaft by hand. I'm not sure what it's supposed to look/feel like, but I can definitely feel and hear crunchiness when it first starts moving. After that the crunching subsides but I feel the each gear tooth engaging (or so it seems). Does anyone know what can cause these symptoms? I assume I have to pull the whole gearcase to get a look inside. Any advice on how to go about that?
Thanks everyone! Hopefully we're in the home stretch now.
Bad news is this means I have to start thinking about the lower unit, crankshaft, etc.
So I have a few questions before I get started.
1) I stuck a borescope up the lower unit to get a look at the drive gear. It looked pretty darn rusty. Not irrecoverably so, and I'm pretty sure the crankshaft would still engage, but it's worrisome. Is this normal? Do I need to replace it, and if I do have to replace it, how difficult/time consuming is that? I was really hoping to keep the powerhead mounted and un-split, so hopefully that's avoidable.
2) I got a lower unit as part of the deal for the motor, but I'm not really clear on what's missing. It appears as though I'm missing parts 27-33 and part 3 of the shift shaft. What am i missing from the prop side, though? What you see in the pictures below is everything I have. Mostly I'm trying to match a part number to that exposed piece with 4 open screw holes on it, so I can tell what numbers above it I need.
Part numbers I'm referencing are here: https://www.marineengine.com/parts/...rts/mark-35a/all/gear-housing-assembly-page-1
3) The lower unit sounds very...crunchy when i spin the crankshaft by hand. I'm not sure what it's supposed to look/feel like, but I can definitely feel and hear crunchiness when it first starts moving. After that the crunching subsides but I feel the each gear tooth engaging (or so it seems). Does anyone know what can cause these symptoms? I assume I have to pull the whole gearcase to get a look inside. Any advice on how to go about that?
Thanks everyone! Hopefully we're in the home stretch now.