Frozen shift shaft joiner on 25hp mariner made by Yamaha

hundee r1

Petty Officer 2nd Class
Joined
Mar 24, 2010
Messages
158
Dont know if this is the right forum to post in but here goes:

Guys, just got a call from my boat mech who is attempting a routine impellor swap in my 1985 25hp Mariner (made in japan by yamaha).
Reckons he has tried everything to undo the joiner in the shift rod to drop the leg but its Frozen. Reckons he has tried heat, all sorts of penetrating fluids, it just wont budge. Said if he tries any harder it may snap the shaft, meaning a labour intensive and thus expensive repair bill cos the power head has to be removed to install a new rod.

The motor is in real good nick and runs well, but I dont wanna spend $600 fixing a broken shaft, on the same token, Ive had it for close to a year and should probs do the impellor soon for peace of mind. Not to mention it turned a few turns and the gears now dont select properly. Basically, I had a sweet running motor that didnt miss a beat that could now be pile of non usable crap unless I spend lots on it. Just because I was doing the right thing and being preventive not reactive.

Im thinking my only option is to very carefully cut / grind the joiner of the shaft with a dremel, run a tap back over the thread and then re install it with a new joiner but getting access to it may be an issue.
Any other ideas? How hard is it to pull the power head?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: Frozen shift shaft joiner on 25hp mariner made by Yamaha

power head removal is not hard if the bolts come out OK and not snap off.

what did you mean by "the gears now dont select properly" did his trying to remove mess something up in the lower unit?

What kind of heat did he use? may need a ox/cel not just a propane
 

hundee r1

Petty Officer 2nd Class
Joined
Mar 24, 2010
Messages
158
Re: Frozen shift shaft joiner on 25hp mariner made by Yamaha

He used oxy to heat up, reckons he had it cherry hot. Spoke to the fitters here at work, said it will never come of now:(

It is stuck in forwards gear now, that is why I cant just put it back together and motor away. He said its cos he got a few turns on the joiner before is siezed, thus I believe making the shift rod "longer". Bit hard to tell cos I dont have it in front of me atm:redface:
 

EAVES

Petty Officer 3rd Class
Joined
Feb 28, 2009
Messages
75
Re: Frozen shift shaft joiner on 25hp mariner made by Yamaha

I would first try to cut the threaded "joiner " on both port and stb side to remove and ck the threads bc it sure has no chance of removing it now since its been hot...
 

hundee r1

Petty Officer 2nd Class
Joined
Mar 24, 2010
Messages
158
Re: Frozen shift shaft joiner on 25hp mariner made by Yamaha

Well guys, it seems miracles happen. They got it undone and put it all back together with a new impellor. Just hope it all works out and my gears select properly and my motor pumps water. Find out next week. Thanx to all:)
 
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