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Siezed drive shaft stuck in powerhead unable to remove

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firedoctor

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"I have a Yamaha 90hp 1986 tha

"I have a Yamaha 90hp 1986 that has the drive shaft siezed to the power head. I realy mean she's stuck. All 11 bolts have been removed and the rear does seperate a little but the crank is well and truly stuck. I have with only just not broken anything, used a engin lift on the fly wheel and bolted the engin to the ground, blasted a CO2 fire extinguisher in the existing 12mm gap to try and cool the drive shaft just under the power head and tapped the drive shaft, still no go. The advise from the local yamaha guy is to cut a hole in the lower unit and cut the shaft with a Sabre saw and then have the shaft re-joined. Where would the best place be to cut the shaft if this is a feasable solution. The rest of the engine is all sweet. Half way down the leg looks posible by the flat area befor the leading edge, is there any exaust channels I need to look out for. I had the enging at the Yamaha workshop but due to time it would cost a fortune in labour. Help someone.. Thanks"
 
"Is there enough room to get a

"Is there enough room to get a propane torch in there? Maybe if you heat the shaft it will loosen afer it cools.

Or, spray it really good with penetrating oil and have patience. Maybe stick a blunt air chisel in there and use it to vibrate the shaft?

Just off-the-wall suggestions here, I'm not saying that they won't cause damage, but sounds less severe than what you suggested."
 
"Thanks bill, any idea's w

"Thanks bill, any idea's will help. there is only about a 12mm gap as the cast iron steering base is in the way. I am going to give the heat treat a try now, the blunt air chisel is a good idea and will think how to get around that with the limited space. I won't blame anyone if I break anything. Any suggestions might just be the one."
 
"I tried heating, tapping agai

"I tried heating, tapping again. no go.... the heat does not get close enough to the area where its stuck because of the lower bearing seal housing. I now have the motor upside down and got have been spraying some penitrating lube. I will leave over night. If I have to cut the shaft I can cut it just under the cast iron steering bracket thing, a tight squeeze but should work as a last resort instead of my privious idea."
 
"Thanks, I will have to pretty

"Thanks, I will have to pretty much have to reconnect and install the carbs and electrical gear oil pump and outer exaust covers etc as the guy at the yama work shop has already dismantled this all. A guy at another marine place suggested this but because the engine is almost all apart I did not do so. What I could do is maby just turn the engine over with the starter. If I do this do you think I should keep the plugs in and still have all the power head bolts off and the lower under a biy of thension? I have some time the next few days so maby I might fit all the stuff on again, what do you think."
 
"Bad news, I ended up cutting

"Bad news, I ended up cutting the drive shaft as I am sure that i would have caused more damage. Any body got a second hand shaft for sale?
The second problem was to remove the bearing carrier, no go with a 5.5 pound slide hamer and heat so the motor ended up at another outboard place where the guy had made up a special jig (2T)for this purpose so the good news is I still have a complete motor minus the drive shaft. I will pick up the parts and continue with the project to rebuild the gearbox so I am ordering a full set of lower bearings and seals. Thanks I will keep updated"
 
"Reading these posts it occure

"Reading these posts it occured to me that if possible, it is probably best to try to remove the lower unit at the end of the season rather than in the spring. If you were to need a water pump it would probably best to do it before winterizing the motor rather than 6 or 7 months later in the spring. It would seem that if any water did get between the crank and the driveshaft, there would be less chance of corrosion occuring if the motor were not allowed to sit for any extended period."
 
"Thanks Bob, all make sense no

"Thanks Bob, all make sense now as I did not know much about outboards.I have learnt a hard lesson. The motor had been standing for about 2 years, and no wonder it was stuck. After seperating the lower end, the seal inside the lower bearing housing had literaly rotted through due to the spring steel rusting and destroying the rubber. cheers"
 
"Hi Bob thanks 4 the advise.Yo

"Hi Bob thanks 4 the advise.You are correct and because of my ignorance this has happenned. I have now almost completed the work after having joined the drive shaft again. The engineering shop pinned it in the centre and then welded the shaft in a lathe to balance it. I cleaned all the parts myself and asembled most of the motor. I had the boat shop assemble the gearbox although easy, I did not have the correct tools to do so properly. To all thouse out there, do that extra mauntenance every season and avoid my mistakes. i have learnt heaps. cheers"
 
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