Lower Unit Removal on Johnson 225 - Page 2

Monkey Butler · #11 08-07-2012, 11:36 PM

Okay, I might be talking out the wrong orifice here but this is more ancient history than modern science.

The key is to use wooden wedges and wait.

Why?

Wood will expand and contract relentlessly with changes in humidity. The Romans, Greeks, and even us Polacks (I think) used this method to quarry rock. Goggle it if you don't believe me.

One thing, a wide metal thingy, like a putty knife blade between the wood and the lower unit case will spread the load and keep the wood from just compressing.

Wood, moisture, wet, dry, rinse repeat.

boatrookie · #12 08-08-2012, 07:29 AM

Thanks for the info. I have got some wedges in it now and slowly working with it. The problem is I only have about an 1/8" in. gap right now, so getting something in there is proving to be fairly difficult. I will keep at it though.

boatrookie · #13 08-12-2012, 02:32 PM

Ok, so I tried running it with all the bolts out today. I put it in gear back & forth and nothing. I am going to try something else I had an idea about. My question is should the shifter be in forward, neutral or reverse before I disconnect it or does it matter? What I am going to do is put threads in the the bottom of the lower unit where the 4 bolts go in from the bottom (currently not threaded) . I am going to put a piece of metal in between the lower unit and middle section then SLOWLY tighten my new bolts upward pushing against the metal pieces and see if it will push the lower unit down. Any thoughts about this or should I not go this route?

Monkey Butler · #14 08-12-2012, 04:44 PM

Sounds like a stroke of genius about using the bolts taht way. I did something sililar to pop the powerhead off of my old Yamaha.

It's certainly less drastic than cutting a window in the midsection and torching the driveshaft in half, which I have only heard about...

RidgeRunner · #15 08-13-2012, 06:53 AM

I sacrificed a midsection once to free up Reelapeelin's powerhead. Did save the lower, but that turned out to be toast too, what a PITA. I feel for you, sounds like you have a plan. Saw a guy turn his mota upside down hung by the lower with the powerhead just above the pallet below. I thought he was kinda nuts but it worked out. His theory was the Blaster he was spraying on the driveshaft was running down into the splines and working on the corosion and the powerhead was heavy enough to do the rest.
I always liked hanging the rear of the boat with the flywheel but it requires removal of the powerhead bolts, cherry picker setup and the replacement of the powerhead gasket. Tons more work but gives you lots of pulling power/leverage.

boatrookie · #16 08-13-2012, 09:46 AM

but as far as the shifter linkage, should I have it in forward, neutral or reverse prior to removing it again or does it matter it's position?

RidgeRunner · #17 08-13-2012, 10:59 AM

To me, I don't really care what position it is in on the Johnrudes, the way the linkage hooks up it can only go back together one way right. Mercs are different with the splined shift shaft attachment at the foot it matters, BUT not on your motor. You can always remove the shift cable from the saddle to make the linkage line up after the repair/maintenance.

boatrookie · #18 08-13-2012, 11:27 AM

Cool, thanks for the information. I am going to give my idea a shot tonight, and see what happens. I have been thinking about it and I keep leaning torwards just applying a little pressure everyday on the bolts rather than just wrenching them down all in one day. I am hoping my strategy works as I am quickly running out of ideas.

Blue_Runner · #19 08-13-2012, 11:43 AM

Be very carefull not to muck up those threads. Not very hard to do.

I had one disobey me one time. I ended up taking it to the shop and they got it off but did not tell me how.

boatrookie · #20 08-16-2012, 07:17 AM

One last question before I proceed with my plan on trying to remove the lower unit. I was thinking about drilling a 11/16" hole in the center part of the engine up torwards the top where it meets up with the actual powerhead section so that I could see the driveshaft and hopefully be able to get some penetrant on the splines. I will lower the nose of the trailer to the ground and tilt the motor all the way up to help. My question is what is normally behind that section or is it just hollow? I can come back later and put threads in that and just put a bolt in it when I am through to plug the hole I made, I just want to try and get something on those splines before I start with the bolts. Your thoughts as they are always appreciated and helpful.