Powerhead fused to driveshaft

[robc]

I have been trying to take the powerhead off of our 1991 Johnson 200 v6 engine to see if we can replace a seized piston. Ten years of running in the ocean has rusted the driveshaft to the crankshaft and no amount of prying is taking it off. We are trying to avoid cutting it off with a sawzall to save the driveshaft. <br />Is there any kind of penetrating oil or way to heat up the joint to unfreeze the rusted shaft?<br /><br />robc<br />

 

[DJ]

Re: Powerhead fused to driveshaft

robc,<br /><br />About the only thing you can do is turn the engine upside down and soak the joint with pentrating oil. Even at that, the prognosis is not that good.

 

[robc]

Re: Powerhead fused to driveshaft

djohns19,<br /> thanks for the reply...<br /> if we go ahead and cut it off, would you use a sawzall to do it and how hard/expensive is it to replace the driveshaft?<br /><br />robc

 

[Walker]

Re: Powerhead fused to driveshaft

I realize its too late for you, but your problem is one of the reasons I put in a new impellor each year. Keeps lower unit bolts from freezing up and I grease the drive shaft head each time. Walker

 

[DJ]

Re: Powerhead fused to driveshaft

robc,<br /><br />If you cut the shaft, your only option is to have the lower unit rebuilt with a new shaft. <br /><br />You may be able to buy a rebuilt lower unit but expect to "take a hit" on the core value of your old one with a cut off driveshaft.<br /><br />I would cut it, after letting it soak and have given up, and go with a rebuilt lower. You may have to do some serious surgery on the powerhead once you get the two seperated.

 

[robc]

Re: Powerhead fused to driveshaft

it sounds like we would need to find a rebuilt lower drive if we cut the drive shaft. we got a price of $4700 for a new powerhead and another $3000 to install it.<br />Would it be best to buy a complete new motor? in our case approx $12,000?<br /><br />robc

 

[Greg Lawrence]

Re: Powerhead fused to driveshaft

well i would try to salvage all you could. get it running, and go for a new one. a big bombadier 250 or so.

 

[Greg Lawrence]

Re: Powerhead fused to driveshaft

btw theres nothing i couldnt get apart with penetrating buster and a small propane torch. seriously you have to try it.. ive soaked things every day for two weeks to get it. just squirt it in the evening and morning, then every few days squirt it and apply some heat to wick the penetrant in there.. penetrating buster is about the best youll find...and liquid wrench is good too.. i guess id just suggest to go slow whatever you do.

 

[robc]

Re: Powerhead fused to driveshaft

Ill try the soaking in penetrating oil<br />thanks

 

[castneter]

Re: Powerhead fused to driveshaft

i feel your pain!! the same happened to me and my 87 140hp evinrude. ill tell you a couple of things about my experience. do not try to pry on the powerhead at the exhaust adapter!!, the adapter will crack for sure. i tried to break the p.h. loose by pulling up on it with a comealong attached to an a frame, but all i did was lift the entire boat off the trailer. i finally took out the sawsall and cut it off. you will be cutting through the exhaust housing as well as the crankshaft and shift shaft. then i removed the remains from the transom and turned it upside down and applied many applications of a product called "p. b. blaster". if you have access to a welder you can fashion a slide hammer by putting a iron weight or simalar object on the shaft and welding some other object on the end of the shaft to serve as a stop. i didnt have a welder so i used a grinder to notch both sides of the shaft so my vise grips would not slip off as i wailed on them with a hammer. i finally got the shaft out. i had to replace the lower unit and shift shaft as well as the exhaust housing. it was a pain in the *#$ but i am still running the motor 4 years later and am a happy lad. let me know if you dont get any of this explanation. castneter

 

[castneter]

Re: Powerhead fused to driveshaft

i feel your pain!! the same happened to me and my 87 140hp evinrude. ill tell you a couple of things about my experience. do not try to pry on the powerhead at the exhaust adapter!!, the adapter will crack for sure. i tried to break the p.h. loose by pulling up on it with a comealong attached to an a frame, but all i did was lift the entire boat off the trailer. i finally took out the sawsall and cut it off. you will be cutting through the exhaust housing as well as the crankshaft and shift shaft. then i removed the remains from the transom and turned it upside down and applied many applications of a product called "p. b. blaster". if you have access to a welder you can fashion a slide hammer by putting a iron weight or simalar object on the shaft and welding some other object on the end of the shaft to serve as a stop. i didnt have a welder so i used a grinder to notch both sides of the shaft so my vise grips would not slip off as i wailed on them with a hammer. i finally got the shaft out. i had to replace the lower unit and shift shaft as well as the exhaust housing. it was a pain in the *#$ but i am still running the motor 4 years later and am a happy lad. let me know if you dont get any of this explanation. castneter

 

[Dhadley]

Re: Powerhead fused to driveshaft

4700.00 for a powerhead and 3 grand to install it?????? You're kidding.....right? Why would you replace the powerhead instead of rebuilding? And why would you replace the entire lower unit just because you cut the driveshaft? <br /><br />We are freshining up a cherry 97 200 Evinrude we'll sell for 6200.00. Maybe it should be 8200.00. <br /><br />Or.................?

 

[robc]

Re: Powerhead fused to driveshaft

if I cut the driveshaft with a sawzall to get the powerhead off of the lower unit, I was under the impression that just the drive shaft could be replaced.<br /><br />We are going to take the powerhead to a technician to see if he can rebuild it before laying out $4700 for a new powerhead. If the powerhead CAN be rebuilt and the technician reassembles it, what steps and/or teesting procedures do we need to do when reassembling the powerhead on the lower unit? <br /><br />robc

 

[Dhadley]

Re: Powerhead fused to driveshaft

First and most important you MUST determine why the piston stuck. Remember the damaged piston is a RESULT not the CAUSE. This is why its important for a qualified tech to do the entire job from start to finish. <br /><br />Good luck!