Lower unit stuck

drbatts

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This probably isn't going to help but watch it anyway. The last section is the worst case scenario:(

One of those videos towards the bottom is my old boat, always cringed watching my mechanic wail on it with a mallet. But he got it off.
 

SkunkBoat

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Hmmm. OK, I didn't pick up on that. So... thinking through this... I'm kinda "writing outloud" as I think... it might be pot luck to get a chemical past the piston rings and to the right spot... I'm trying to envision if a chemical (if the piston was stopped to expose the exhaust port) would even make it to the end of the crank? I mean, the crank lower end is exposed to the environment (hence the problem) whereas the exhaust takes a different path. And even so, the driveshaft is a male and the crank is a female so while some of the chemical may wick it's way in, I don't think it's going to make it there at all. Am I thinking through that correctly?
I THINK the intake covers the crankshaft with fuel/oil. Yes?
 

mjm1957

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The driveshaft goes into a blind hole in the end of the crank. When you reassemble you only use a small amount of grease on the splines and not the top of the driveshaft.
 

Meanwhile

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If you hit the top of the flywheel with a heavy deadblow is there a chance the shock might carry to that shaft?

I like Kroil as it creeps well, but acetone and ATF might be cheaper.

If you are on FB, check out Yamaha Tech Talk, post the question and watch for an answer from Wayne Shoup, the admin. Good source of Yami info.
 

DennisG01

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Here we go! The only bolts that are in are (4) of the main ones - and they are only halfway in.

1CF5B7BC-D8CF-474B-B504-222A793DA5CB.jpg


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43C2531C-1A49-4CDD-972A-2170F5C7F882.jpg
 
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seasick

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Dennis,
if there is a small gap, you may have luck using a bunch of wooden wedges. Whack them in a crisscross pattern and see if you make any progress. I would not hit the drive wheel or crank.
 

DennisG01

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Dennis,
if there is a small gap, you may have luck using a bunch of wooden wedges. Whack them in a crisscross pattern and see if you make any progress. I would not hit the drive wheel or crank.
Yup - I have few small small wedges in the front and back. They're not in very far as this point - the front gap is maybe 1/4" or 3/8" while the back gap is about half that.
 

steveditt

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You can fix the problem maybe and then something else fails your back to not having a boat , Friend recently had shop attempt to remove it then cut the shaft purchased a rebuilt lower unit and that failed during the season .Good luck with your decision !
 

DennisG01

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You can fix the problem maybe and then something else fails your back to not having a boat , Friend recently had shop attempt to remove it then cut the shaft purchased a rebuilt lower unit and that failed during the season .Good luck with your decision !
Anything can happen. But right now I KNOW I'll eventually be facing a problem when the impeller craps out. I'm not worried about "what ifs" Those will get dealt with when/if they happen.
 

Halfhitch

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Dennis, have you had any customers ask, just what the hell kind of experiment you're doing, when they see your contraption?
 

freddy063

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I had trouble a few back, the bushing was stuck on the shaft, Theirs was a lot of build up stopping the shaft from moving . You say the unit comes down a little. Can you fit a small plastic tube up the lower unit inside to spay pb blaster up the hose to hit the bushing?