Lower unit stuck

drbatts

Well-Known Member
Joined
Nov 30, 2008
Messages
791
Reaction score
165
Points
43
Location
CT
Model
Express 305
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

Well-Known Member
Joined
Oct 12, 2017
Messages
4,139
Reaction score
1,435
Points
113
Location
Manasquan Inlet NJ
Website
www.youtube.com
Model
Express 265
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

Well-Known Member
Joined
Aug 1, 2015
Messages
45
Reaction score
15
Points
8
Age
67
Location
Long Island
Model
Seafarer
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

Well-Known Member
Joined
Feb 16, 2014
Messages
564
Reaction score
105
Points
43
Location
Warren, OR
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

GreatGrady Captain
Joined
Sep 1, 2013
Messages
6,744
Reaction score
1,188
Points
113
Location
Allentown, PA & Friendship, ME
Model
Offshore
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


02988C3B-663F-4DFF-B6DB-2EC75787C4A5.jpg


43C2531C-1A49-4CDD-972A-2170F5C7F882.jpg
 
  • Like
Reactions: PointedRose

seasick

Well-Known Member
Joined
Aug 19, 2008
Messages
9,073
Reaction score
1,293
Points
113
Location
NYC
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

GreatGrady Captain
Joined
Sep 1, 2013
Messages
6,744
Reaction score
1,188
Points
113
Location
Allentown, PA & Friendship, ME
Model
Offshore
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

Well-Known Member
Joined
Nov 11, 2012
Messages
144
Reaction score
22
Points
18
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

GreatGrady Captain
Joined
Sep 1, 2013
Messages
6,744
Reaction score
1,188
Points
113
Location
Allentown, PA & Friendship, ME
Model
Offshore
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

GreatGrady Captain
Joined
Nov 11, 2017
Messages
1,347
Reaction score
421
Points
83
Location
Venice, Florida
Dennis, have you had any customers ask, just what the hell kind of experiment you're doing, when they see your contraption?
 

freddy063

Well-Known Member
Joined
Mar 26, 2007
Messages
566
Reaction score
31
Points
28
Location
Maine
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?