Stuck drive shaft

[rsw08]

I need some help with a Yamaha 2000 OX66 250HP. It came with a boat hull that we just bought and for the price we paid the motor was basically "free". That being said, the guy we bought it from didn't know much about the history of the motor (because he had just bought it himself and then decided he didn't want a project boat), only that it was running fine and then the water pump went out and he couldn't remove the drive shaft to get to it. He sawed the lower unit off I guess in order to have better access to it but he was unsuccessful in removing it from the crank area. So now my husband is trying to free it but he is not having much luck either. We took it to the local Yamaha dealer/mechanic for an opinion and he said that the motor itself looks to be in great condition.

My questions are: is there a secret to removing this thing that we don't know about?
Is is worth messing with it at all? I'm afraid of the further damage that we may be causing just trying to remove it. Basically the motor was free, so if we can fix it great but if not I guess we'll look at parting it out and put that money towards a new motor.

Thanks in advance-Rebecca

 

[cousinabe]

Re: Stuck drive shaft

Am I understanding this correctly?

You tried to change the water pump impeller and could not get the lower unit to separate. The lower unit was then cut off to find the drive shaft is stuck in the powerhead? Was it a clean cut and now there is just a cut drive shaft rod to work with?

can you post a pic of this?

http://forums.iboats.com/showthread.php?t=141817

 

[triumphrick]

Re: Stuck drive shaft

The 250 os66 is one of Yamahas better motor good for thousands of hours of use. It is a shame it has been butchered??
You can probably salvage the powerhead.
Usually a brass hammer tapping around the shaft as close to the powerhead will help. It is hard to tell what you have without pictures...

 

[rsw08]

Re: Stuck drive shaft

Yup I think thats correct...here are some pics (at least I hope it works, I don't do this often )

 

[rsw08]

Re: Stuck drive shaft

Sorry...here is one more. The quality isn't so good because I'm using my camera phone.

 

[getusummm]

Re: Stuck drive shaft

You have a few options here. But you need to be somewhat careful. I had a 250 with a stuck drive shaft also. By the time I got mine out, it had actually pulled the splines out of the crankshaft, so I was left with a bad crank and a bad lower unit. I would start by cutting the driveshaft off flush or close to the crank and drill a hole all the way through the center and then tap it for a bolt. I think 5/16nc or 3/8nc would be a good starting point. The crank is not terribly hard, you just need a good sharp bit with lots of lubrication and judgement with speed and pressure while drilling. I would also soak the heck out of the driveshaft/crankshaft wile upside down with something like PB Blaster or similar. Once tapped, use a slide hammer screwed into the driveshaft and try that. If that doesnt work, you could keep drilling and tapping it for larger bolts. The hole through the center is going to relieve pressure on the splines and should help it come out. You could even drill it or grind it using a dremel, until just a thin shell is left and use a small punch to break the remainder out using care. I am sure there will be plety of other good suggestions coming shortly. I am not sure of the seals and bearings in that location, so I would be very careful using heat. I do know the dampner has rubber on it, so it would burn easily using heat if the flame ran across it.

 

[Marion Moore]

Re: Stuck drive shaft

Good pointers on the slide hammer. Normally you would want to whack the crap out of a stuck part with a large hammer but I would not do that considering you would be basically hitting your crank shaft, bearings, etc.

Another thing to consider is the lower unit. You will either have to rebuild the one you have with a replacement drive shaft. I doubt you will find a used drive shaft. Another alternative is to find a used lower unit. As long as your LU is sound you could probably sell it for parts. I know the engine was free but if money is tight like it is for most people right now you may want to look into the cost of the lower unit. Also consider how long it might take to find one.

 

[rsw08]

Re: Stuck drive shaft

Thank you very much for your suggestions. A friend of ours also recommended using a slide hammer so we are going to try that today. I really hope we can get it to work!

 

[cousinabe]

Re: Stuck drive shaft

let it soak in pb blaster penetration catalyst first... maybe you won't have to go through all of the other steps...

a new drive shaft runs ~300 at www.boats.net
a rebuilt lower unit sells for ~1500.

be prepared to spend some $$ on getting that motor up to snuff with all filters and pumps, maybe O2 sensor, etc. And if you're gonna do it yourselves, get a Yamaha OEM service manual.