Stuck Lower Unit on '72 John 85hp?

[ADK_Boater]

Hey everybody,
I've got a 1972 Johnson 85hp with hydro-electric shift.
I think my lower unit is stuck. I removed the trim tab bolt & The bolt in front of the trim tab. The four bolts on the port and starboard sides, and the two wires at the knife connectors. Now, I understand that there is a bolt underneath the trim tab. At least that is what my Clymer manual says. There is a recess under the trim tab, but instead of a bolt, I found a headless bolt, or something. Here is a pic. Has anybody seen this before? By the way my lower unit won't budge, not an inch.
There is more of a recess than appears in the pic between the surface and that "headless bolt" or whatever it is. Probably a quarter inch or so deep.
I don't know how I'm gonna get the unit off.
All I can think of, if in fact it is a bolt, is to use an extractor. But, before I do I was wondering if there is an easy way I'm overlooking.
Honestly since that headless bolt has a somewhat smooth surface I don't believe it is sheared off.
I'm stumped.

 

[ONERCBOATER]

Re: Stuck Lower Unit on '72 John 85hp?

1st suggestion.... use clymer for target practice.... look on ebay and what have you find factory manual repair/service for your engine... clymer and seloc stuff too many models into too lil space with generic pics that dont fit whatever your working on.
that said..... not familiar with that particular model... but you may find that on the other side of that "broken off bolt" is an allen head in a recess or hole.... look carefully. I think you might be pleased with the result.
If someone contradicts me listen to them i just making suggestion from prior exp with outboards but dif models. also extractors are often more trouble than worth on outboards.... and if you bust the extractor in the hole you drilled you will be up the proverbial creek. if you find that you must drill for the extractor i would humbly suggest using left handed drill bits and plenty of lube.... center punch... drill carefully to center with a small drill.. then use a larger one and so on til you reach the threads.... likely it will spin out before that. also suggest cobalt bits... not coated and true cutting oil...oh.. and a bit sharpener cause the stainless they make most of the bolts from does bad things to drill bits and it is really hard to put entire engine on a drill press so you stuck with higher speeds and lighter cuts.... bad for drill bits.

on closer inspection of that bolt there is evidence of a head and perhaps a lock washer having been there... i thinking it popped off and being held on by corrosion now... please wait for other input beside mine before doing anything drastic. and likely a good time to use penetrating oil so it has time to soak in.

Sean

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Yeah, I agree. The Clymer is not what I had hoped for. The good thing about them, unlike an OEM service manual is that they assume you know nothing. However the pictures are not good, and I couldn't even find the firing order in that thing. I'm gonna post a new picture tomorrow when I have some natural light so I can see what angle I'm taking the picture at. But if anybody knows what that is, let me know.
Thanks evryone.

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

I took a look at the exploded parts diagram, and it clearly shows a full bolt in that location.
If anybody knows otherwise let me know.
I'm gonna try to get a better pic now and post it here. Alright I got the pics here they are.
The edge of this mystery bolt looks beveled. so, that is confusing. Also, wouldn't the part that is threaded, if this is a bolt, be in the exhaust housing? Maybe thare are some threads on the lower unit holding it on, but if not, then it should slip right off.
Still confused.
I have a friend that will let me borrow his extractor after work, but if someone knows the solution, please let me know. I've never seen this before.
Thanks!

 

[eavega]

Re: Stuck Lower Unit on '72 John 85hp?

I've owned a 1972 Evinrude 50 HP that had a recessed bolt in that location. I currently own a 1976 70 HP Johnson that had a bolt in that area. I would assume its a safe bet that is the bolt holding your LU in place.

Rgds

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Thanks for the reply.
The part that gets me is how that thing got in there in the first place.
Now I'm wondering how I'm gonna get it out?
That unit is on there good! there are no other bolts or fasteners. I'm pretty sure that's it.
I guess I'll use the extractor later.
I still hope somebody is gonna chime in with the magic answer. LOL!

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Anybody?

 

[ONERCBOATER]

Re: Stuck Lower Unit on '72 John 85hp?

please note i advised to drill rather than use an extractor. generally you will find that the threads themselves are not the culprit, but the smooth section of the bolt that gets corrosion on it where it interfaces with the aluminum.... the Stainless steel/aluminum combination set up a galvanic reaction... on the outside of the engine the/a zinc or magnesium anode will take care of that as it erodes to protect the aluminum, inside the hole where the bolt is there is no protection and a damp/wet environment. the corrosion takes place there and is what causes the bolts to lock up... many times causing the bolts to break off should one not be careful in their removal. I would guess the previous owner or shop broke this one and chose to leave it rather than attempt to remove it. likely the previous owner also paid for a impeller he/she didn't get. thats all moot at this point.
the reason the end appears beveled i would guess is that the threads are either rolled or cut (depends on bolt manufacturing method cheaper is rolled) and when snapped will appear beveled.

I wish you the best of luck with your screw extractor, just remember if you break it off in the hole that it is much harder than your drill bit and the net result will likely be a trip to the local machine shop.

Sean

 

[dazk14]

Re: Stuck Lower Unit on '72 John 85hp?

If you've got all the bolts off, it is being held by that broken bolt.

It was likely broken upon removal when it received it's previous water pump. Lacking a gas torch, the owner just used the balance of the fasteners - which is probably fine.

Easy-outs and outboards result in broken easy-outs.

If you have a good torch, you can quickly heat the area surrounding the stud and bounce on the the cavitation plate with both feet. Thin paint scrapers can usually be used to wedge between the lower and mid-section (front/rear) and a rubber mallet hitting side-ways on the upper portion of skeg, etc.. If you've gotten a wedge in there, or a fat kid standing on the cav plate, an air hammer with a straight pencil shaped bit, would make quick work of that. Hammer the stud upward.

If you have the patience, a wicking type penetrating oil - Kroil, pb blaster - can be helpful in your type of situation.

Have a landing pad for that lower when it eventually comes off.

There are other ways, but this will get you started.

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Wow dazk14, That sounds...intense!
I have tried spraying penetrating fluid on it and letting it soak. I've also hit it strategically with a rubber mallet. My friend just texted me to say I could borrow his extractor kit tonight, as long as I replace the bolts that I stripped on his puller kit when I took off my flywheel LOL.

I guess I don't know what you mean by an easy-out. I'll try to google that one.

ONERCBOATER, Thanks for the extra info. That all makes sense now. I'll try to be as careful as possible. If the bolt doesn't come out easily, then I'll use a little of the dazk14 technique.
I'll let you all know how it turns out later.

Thanks Again Everyone!

 

[AlTn]

Re: Stuck Lower Unit on '72 John 85hp?

lacking a fat kid, I used a piece of wood on the a/v plate and pounded it with a 2lb. ball pen, switching side to side, front to back, just to gain a small crack, then hammered a sharpened scrapper into that seam..then back to hammering the wood and moving up in wedge size...it eventually came free to the extent I could pull the lower unit off...this was on a 1971 25 hp that all four l/u to exhaust housing screw heads had twisted off.
To remove the now "studs", I heated the screw housing area with a map gas torch, and a combination of vice grips and pb blaster made it relatively simple and quick to unscrew them.

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Nice, that sounds do-able. I don't have any fat kids handy either. I do have wood and a mini-sledge. I'll take it easy with the mini sledge. I'm gonna go work on it, we'll see what happens.
Thanks!

 

[ONERCBOATER]

Re: Stuck Lower Unit on '72 John 85hp?

easyout=extractor.... like crescent=adjustable spanner

Sean

 

[ADK_Boater]

Re: Stuck Lower Unit on '72 John 85hp?

Victory!
Mini-sledge and scrap 2x4 with a downward blow=success!

I can't thank everybody enough!
I probably would have been a dainty wuss about it without everybody's suggestions.
I'll let everybody know when it is finally running. Hopefully sometime this weekend.
THANK YOU!