Should I just break the bolt?

TwoRivers

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Hello all. I've been doing some maintenance on my 1989 Johnson 70 hp. While trying to remove the lower unit for a water pump upgrade one of the bolts broke off. It's one of the bolts toward the middle of the lower unit. I was able to remove the bolt up inside of the anode cavity and the two bolts toward the front of the lower unit.
The remaining middle bolt won't let go and it seems likely to break as well. I really tried to be patient with the broken bolt. I sprayed it with penetrating liquid, let it set, sprayed again, let it set. Loosened a little , tightened a little. Added some blue flame, loosened, tightened, loosened. Then it broke.
I don't think I can be any more patient?
Question, should I just break the other bolt off and deal with the eventual consequences or does somebody have a method for removing these soft stainless bolts from the aluminum housing?
Also, what are the consequences of breaking the bolts? How am I going to get the broken bolts out?
thanks in advance.
rob
 

racerone

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Use ample heat on the aluminum housing.----That will expand more than the bolt and it will come out.
 

TwoRivers

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Ok, put lots of heat to it (MAP). Got the housing hotter than I was comfortable with. Bolt started working loose. Then it snapped. Both are broken up inside the housing with nothing to grab onto. Can these be drilled and tapped?
Or, is my only option to remove the mid section (power head has to come off) and take it to a shop to remove the broken bolts.
I know lots of guys have broken off bolts, I've followed the threads here but they just seem to end without ever finding out what happened?
Any and all ideas appreciated.
thanks
rob
 

gm280

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Not seeing how it broke off, I can't make any real opinions as to how you may get the broken parts out. If you can get to it and drill it out without damaging the surrounding material then go for it. But if there is a possibility of damaging more then you can fix, then take the effort to remove the mid section and pay to have it removed. JMHO!
 

racerone

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Find a piece of 1" bar stock / flat plate.---Measure the gearcase bolt hole spacing.---Make a drilling fixture to keep the drill centered.---------No need to take this to a shop at all.
 

dazk14

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Jul 22, 2008
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Find a piece of 1" bar stock / flat plate.---Measure the gearcase bolt hole spacing.---Make a drilling fixture to keep the drill centered.---------No need to take this to a shop at all.

A few sizes of Cobalt(not just coated) drill bits are a must. $25 investment. Don't overheat, cutting oil helps. Drill in stages. I believe Lowes/Homepo now stock these.
 

TwoRivers

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Thanks for the replies and tips The bolts broke off just about flush with the mid section. I was able to drop the lower unit.
Started to drill one bolt out and I was just about through the bolt with an 1/8 bit. I was taking my time and didn't seem to be putting too much pressure on the bit when BAM. The bit broke off. There was a tiny amount of the bit still sticking out and I tried for about an hour to grab hold and back the bit out. No luck. Lost my patience and my mind.
Grabbed the welder and tried to tack the bit back together. Goobered it up pretty good. Discovered that the bolts aren't stainless so I decided to build up a weld on top of the bolt and maybe get some vise grips on it. Goobered it up some more. Decided I'm not getting that one off.
Wondering if I can get by with one bolt missing????
Started to drill the other side out. Got about half way through and my drill batteries went dead. While charging, I regained my senses and realized that any chance I have of saving this mid section will require a trip to the machine shop. Maybe they can get the goobered bolt out, maybe not. Perhaps a helicoil? Who knows.
Getting ready to pull the powerhead but I'm hung up on which electrical connections to disconnect and which fuel lines to remove?
Manual says remove the VRO bracket and to only remove the fuel line from the manifold?
Can't figure out if the pump comes out with the powerhead or not.
Need some help, mostly psychiatric.
No better way to spend a cold snow covered Saturday.
thanks again, appreciate the help.
rob
 

gm280

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Seeing how you do have a welding capability, have you thought about welding on a flat bar or something like that on to the blobbed weld you tried on the stuck bolt. It could give you the leverage to break the bolt loose. Just a thought.
 

TwoRivers

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Seeing how you do have a welding capability, have you thought about welding on a flat bar or something like that on to the blobbed weld you tried on the stuck bolt. It could give you the leverage to break the bolt loose. Just a thought.

Thanks for your response. Sounds like a good idea except for the fact that I have more welding capability than welding skill.
Seems like the heat from the torch and the weld plus the gouging, banging, etc. is effecting the surface of the mid section. Some pock marks are developing around the outside of the bolt holes. I think I'm done welding on this job.
Going to HF to pick up an engine hoist to lift the powerhead (no help today). Give me a chance to clear my head some more and spend some more money. This free boat and motor ain't free no more.
Oh well. Never took a powerhead off before, maybe I'll learn something?
rob
 
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rothfm

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Sep 26, 2006
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We all have been there. The manual describes pretty good getting the PH off, shouldnt be too bad unless the ph bolts are salty.

Removing stuck/broken bolts can be an art. In my teardowns ive fount at times its easier to swallow my pride and take it to a shop. I can get most.

I bought an old motor that already had numerous broken off things. I found it easier to take it in and have them removed. A local guy cleaned everything removed all the broken stuff, retapped several. For 100 bucks

Sometimes well worth it. He said he used acid and some electricity or something. Wierd but again, well worth it one i swallowed my pride.
 

gm280

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TwoRiver, just remember there are Heli-Coils and very good epoxy compounds to fix near about anything with OB's. So what seems like a dismal situation, it will all work out in the long run. This too will past...
 

TwoRivers

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Guys, Thanks for the encouragement. What got to me was the fact that I was sooooo close to that first bit all the way through the bolt. I was more patient than ever before. Must have taken me an hour to drill the hole. Then BAM. The bit must have snagged when breaking through the end of the bolt?
Anyways, the sun is shining and there's snow on the ground and the lakes are frozen. Can't fish, can't get any work done outside, so at least this is a good time for this ordeal.
I'll post some pictures once I get the mid section off.
thanks again, enjoy your Saturday.
rob
 

TwoRivers

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Not sure if I need to start a new thread on this one but here's what's going on.
In my effort to remove the power head, I got all the fasteners, hoses and wires disconnected according to the manual (unless I missed something?).
I've got the power head hooked up to the shop crane by the lift hook. There is tension on the power head to the point where the engine stand is coming up off the floor but, the power head won't release from the mid section? Probably being held together by some 26 year old gasket sealer?
I've just got it hanging with tension on it for now.
Any ideas?
thanks
rob
 

TwoRivers

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Did you remove one nut at the back?

Yeah, I got that nut off the stud in the back. That was a tricky one. I let the motor hang from the crane for about five hours. Before I went to bed last evening, I took a rubber mallet to the side of the flywheel and the mid section. Powerhead let loose. Lowered it down a bit then quit for the night. Will try to get mid section to the shop today.
I'm curious about something? While removing the various bolts, I encountered yellow, blue and red thread sealer. The manual only says to use one kind. I'm wondering whether it would be better to use thread sealer or anti-seize especially on the bolts that broke off? Also, is there any maintenance that should be done while I have the power head off? I'm sure I'll need some help getting this motor back together.
Thanks for your response
rob
 

TwoRivers

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Well, I dropped the mid section off at the machine shop. It's an automotive machine shop taking up residence in a NAPA autoparts store. The machinist, whom I've dealt with before wasn't very confident that he could get the boogered bolt out. Said he couldn't drill through the weld I put on top of the bolt and bit? He should be able to get the other one out. Hell, I think I could get the other one out especially since the mid section is now off.
Anyways, I told him to try his best and take his time (time is money). We'll see how it goes?
rob
 

TwoRivers

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Got a call from the machine shop. They got the broken bolts out. Reminded me of Scotty on Star Trek saying it's impossible Captain then fixes it in five minutes.
Good news nonetheless. Anybody recommend any additional maintenance before putting things back together?
What about the tilt and trim unit? Anyway to power it up without the harness that's still attached to the boat?
I'm thinking I'll need a new gasket between the PH and the adaptor? Oh, and two new bolts?
Anything else?
 

bob johnson

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Feb 25, 2009
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I will try to offer up a bit of advice for the next salt water infected outboard... heat is always good....but once you break a bolt free, don't just try to run that thing straight out... Work it back and forth...if you get some movement penetrating oil and then try to thread it BACK in to where it was, then back out past where you were...then back in a little, then back out some more...then back in ......then back out...all the while spraying penetrating oil before you thread back in... the back and forth will help prevent some breakage....NOT all...some bolts just are too corroded and too weak ...some anti sieze when you reinstall should help... make sure it is compatible with your motor and bolts

PS: don't let off the heat just because it started to turn!!

bob
 
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dazk14

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Jul 22, 2008
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966
+1 as Bob J said, HEAT!!! Expect to discolor and/or bubble the midsection paint getting it to expand enough to release if it's stuck enough.

More heat faster is better than a slow poke old propane torch. By the time you've expanded the surrounding parent metal, the bolt will expand excessively - although any heat is much better than none.

The OP should have bought the correct cobalt drill bits as suggested. These cut far quicker and are more amateur friendly, well Pro too.

After that...welding a washer and nut to the broken stub would be the next step. If enough is sticking out, then just a nut. The heat from the welding normally allows the new assembly to loosen quite easily.

He also made the mistake of further dismantling the Powerhead (read: more bolts)...GREATLY increasing the likelihood of creating a parts motor.

For the lower, the best anti-seize is any good quality marine grease.

I'm glad it is working out for the OP and he's a good guy to follow up, and he may as well let folks know what he was charged for the 2 extractions.
 
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