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How to remove the Johnson Bubbleback Exhaust cover?

buckz6319

buckz6319

Regular Contributor
I'm looking for some advice on how to remove the bubbleback exhaust cover from my 1987 Johnson 110?

I have tried every which way to remove this cover only, however I can't figure out how or if it can be removed without removing the power head? The belly keeps getting hung up at the bottom between the casing

I would appreciate any input on this.

thanks!
here are some pics

IMG_20181001_181312 by , on Flickr
IMG_20181001_181240 by , on Flickr
IMG_20181001_181216 by , on Flickr
IMG_20181001_181706 by , on Flickr
IMG_20181001_181715 by , on Flickr
 
Dont you need to remove them both at the same time? The inner plate is also part of the exhaust. The outer cover is a water jacket.
 
kimcrwbr1 said:
Dont you need to remove them both at the same time? The inner plate is also part of the exhaust. The outer cover is a water jacket.
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Well, I really don't need to remove the exhaust manifold, however I think I can get the gasket on the Exhaust bubble back cover without removing that cover completely

thanks!
 
I would replace both gaskets !-----It will also allow you to inspect pistons and rings with both covers removed.
 
racerone said:
I would replace both gaskets !-----It will also allow you to inspect pistons and rings with both covers removed.
Click to expand...

I can understand your point and will do that sir. I'm now waiting on my thermostat kit to arrive and will install it once here then move on to the other
thanks for your input!
 
racerone said:
I would replace both gaskets !-----It will also allow you to inspect pistons and rings with both covers removed.
Click to expand...

racerone I decided that this morning I would take your advice and remove the Water Cover and Exhaust manifold. I started to slowly remove the water cover center bolt and it felt like it was gonna snap and it did. I got the water cover off and removed the exhaust manifold. I have a few pics to share below.

I also removed the thermostat housing, old parts and replaced them with all new parts this morning. I have a few pics to share.

My issue now is that broke aluminum stud. I have removed studs in the past from engine blocks that are cast iron, however not a broken aluminum bolt from an aluminum block. I would appreciate any suggestions on this removal. I have already used penetrating oil and tried the 2 nut trick I have used in the past. I don't have a welded but I do have a lot of tools. I have attached a old pare of Vice grips that is my ''go to tool of choice'' for good clamping force. I started to slowly rock the seized stud back and forth but it's still seized. I sprayed more penetrating oil on the stud for now and came inside to wright this and upload some pics of my progress today.

I would appreciate any help and any input on anything you see that may need attention.
Thanks

IMG_20181006_132204 by , on Flickr
IMG_20181006_132156 by , on Flickr

New thermostat housing gasket on
IMG_20181006_133639 by , on Flickr

My way of holding on all the new parts and covers--it was not as bad as I have read about, however it was time consuming
IMG_20181006_140410 by , on Flickr

IMG_20181006_141005 by , on Flickr
IMG_20181006_135122 by , on Flickr

some pics of me stuffing in some assurance shop towels :)
IMG_20181006_132650 by , on Flickr
IMG_20181006_141641 by , on Flickr
IMG_20181006_141122 by , on Flickr
 
racerone said:
It is not aluminum.-----Therefor heating the surrounding aluminum may help get it out.
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Yep, heat is your friend.

Do you have a welder? You could run a nut down flush to the exposed end of the bolt remnant then tack weld it. With the nut welded on you could use an impact socket and impact driver to knock it loose. I've found when steel bolts (screws) are stuck in aluminum the combination of heat and impact gets things moving. The force pushing in on the impact from hitting it combined with the twist works great.

impact.JPG
 
kevinj said:
Yep, heat is your friend.

Do you have a welder? You could run a nut down flush to the exposed end of the bolt remnant then tack weld it. With the nut welded on you could use an impact socket and impact driver to knock it loose. I've found when steel bolts (screws) are stuck in aluminum the combination of heat and impact gets things moving. The force pushing in on the impact from hitting it combined with the twist works great.

View attachment 18897
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No sir, I don't have a welder at the moment someone took it last year and never returned it-- I do however have some ols LH drill bits and a few Centre bits still around. I will try them tomorrow. I did try some heat and vice grips and all it did was just allow me to snap if off even closer to the block-- Ouch!
 
One of those cordless 1/4 drive impact drivers work good for removing bolts. Just get a socket adaptor and yes the heat from tacking a nut to the bolt may just do the trick. It looks like the carbon buildup is pretty even once you get it up and running be sure and do a WOT rpm test it may be overpropped causing it to burn rich?
 
Too bad it snapped off further. Impact on heated bolts usually works best. Continuous twisting force typically breaks them like you found.
 
If you are going the ' drill it out " route you should make a drill guide of steel bar / plate.-----3/4" and use the 2 holes above to keep it in place.------Put a # 7 drill hole in the guide for drilling out the bolt.
 
Well, I spent some time this morning to try and get the remaining portion of that snapped bolt out. I soaked it with penetrating oil and tried a a couple of chisels to try and twist it out, but to no avail. I then tried my centere drill method (I didn't see your last post racerone until it was too late) and somehow got the whole off center but the LH bit did nothing. I believe that the roundness twisted end of the bolt didn't allow me to make a good center hole even though I put a center punch hole the bit started walking. I usually don't mess up like this, however I guess I just was in too big of a hurry!

so my question is this---
do I really need that center bolt? I was thinking I could just have someone weld up the center hole in the exhaust cover?

IMG_20181007_111039 by https://www.flickr.com/photos/152338949@N04/, on Flickr
 
kevinj said:
Too bad it snapped off further. Impact on heated bolts usually works best. Continuous twisting force typically breaks them like you found.
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yep! I didn't think that would happen I have done many broken screws like that with continuous twisting in and out and have remove them, however I was thinking this one wasn't stuck as bad as it was and it felt like it was freeing up some--- then snapped again. I wonder why it is so seized in the block threads? I don't think it's rusted in there--- maybe someone used some sort of lock tite or maybe it's was caused by the heat? I really don't know
 
Post #18 I asked a stupid question!

so my question is this---
do I really need that center bolt? I was thinking I could just have someone weld up the center hole in the exhaust cover?

Now that I looked at it again I can see part of the exhaust gasket extends down below that center bolt! crap! double crap!!
 
The white powder you see is aluminum oxide.-----That means oxygen has joined up with the aluminum one molecule / atom at a time over the years.------There is now more material there in the threads that when it was new.-----That is why things jam up due to corrosion.-----Rust is iron oxide and here you have aluminum oxide .-----Same process and concept.
 
Ok, now before I do un-repairable damage--- trying to remove this broken screw--- is there anything else I can try? That looks like a SS screw that snapped?

Here is a couple of pics of the area cleaned up and both of the pics are showing what NOT to do! however I did it!
IMG_20181007_144202 by , on Flickr

IMG_20181007_125201 by Dwayne Buckner, on Flickr
 
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Get a center punch and drill a small hole all the way through the bolt dead center ise a punch to flatten the end first. You have it cleaned up good enough to put back together then do a decarb once its running good. Use a drill the width of the inside threads of the bolt then you can chase the threads with a tap to clean the threads. Dont worry too much focus on centering the hole you can always helicoil it if you screw up.
 
kimcrwbr1 said:
Get a center punch and drill a small hole all the way through the bolt dead center ise a punch to flatten the end first. You have it cleaned up good enough to put back together then do a decarb once its running good. Use a drill the width of the inside threads of the bolt then you can chase the threads with a tap to clean the threads. Dont worry too much focus on centering the hole you can always helicoil it if you screw up.
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ok, thanks for the input. I appreciate it! I will try that approach next. I will have to flatten out the end of the screw and will have to get a center punch . I hope that punch does what is supposed too--- being the end of the screw is buggered up at this point.

Man I sure didn't want this headache to deal with--- all I was doing was just checking things out and replacing what I felt I needed to before taking it to the Lake-- heck good thing the friend I'm purchasing it from was ok with me checking things out before payment and I appreciate that...
 
Welcome to the world of maintaining older outboards you will either have fun or just throw in the towel and buy another motor. After learning a few more choice words the rewards are great when your hitting the high spots in the waves!
 
buckz6319 said:
ok, thanks for the input. I appreciate it! I will try that approach next. I will have to flatten out the end of the screw and will have to get a center punch . I hope that punch does what is supposed too--- being the end of the screw is buggered up at this point.

Man I sure didn't want this headache to deal with--- all I was doing was just checking things out and replacing what I felt I needed to before taking it to the Lake-- heck good thing the friend I'm purchasing it from was ok with me checking things out before payment and I appreciate that...
Click to expand...

Are you buying the boat or just the motor?
 
kimcrwbr1 said:
Welcome to the world of maintaining older outboards you will either have fun or just throw in the towel and buy another motor. After learning a few more choice words the rewards are great when your hitting the high spots in the waves!
Click to expand...
Well, Thanks! I have owned quite a few outboards over the years, however I haven't had the pleasure of dealing with a snapped screw :) and I don't throw in the towel easily. I will get it figured out with help for others---
 
That carbon buildup is common usually for a engine running too rich or being over propped. A good tach and volt meter are a must IMO for a safe outing and monitoring engine performance.
 
kimcrwbr1 said:
That carbon buildup is common usually for a engine running too rich or being over propped. A good tach and volt meter are a must IMO for a safe outing and monitoring engine performance.
Click to expand...
yes, I agree and I have a good DVMM but the tach on the boat does not work so I will have to get one, but not until I get this dang screw out. The prop is an SS Raker brand, however I can't remember where the pitch is stamped on it at----
IMG_20181007_085839 by https://www.flickr.com/photos/152338949@N04/, on Flickr
 
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