Cylinder block won't release - any tips?

[Argee]

Firstly, please accept my apologies as this is not a problem with my GS, but with a Suzuki VL125 that I'm restoring for my daughter.

I'm rebuilding the engine and want to replace the piston rings. The rear cylinder block came off without any problem, but the front is stuck fast.
Before we got it, the bike was kept on a dairy farm and was regularly ridden through mud that was 'frequented' by cows......
There is one stud at the front that passes through some of the fins before it enters the block and that has obviously taken the brunt of the 'cow residue'!
IMG_20190105_214151.jpg

I have managed to remove all the other studs (in the hope that it would help) but the block is still stuck fast at the front. I have tried heat (both heat gun.....and butane torch) I have tried 'persuading' it with a rubber hammer, with a metal hammer via a block of wood. I have tried unscrewing the offending stud, but have reached the limit of torque that I dare to apply. I've tried to prying it off with a couple of big screwdrivers (and managed to break one of the fins...is it best to use JB weld or is it better to stick the bit back on by brazing?)
I have also threaded a piece of stainless steel welding wire down the side of the stud and connected a drill to it and managed to loosen a bit of the corrosion by rapidly rotating the wire - but it's still not shifting....

Does anyone have any advice or suggestions of what I can do?

Many thanks in advance.

[GregT]

I'm in dairy farming country too - which is why I won't do farm bikes or quads....

Heat and penetrating oil - repeated. Heat on the case where the stud goes in will help.

If you want to repair the broken fin, it's TIG welding.

[greg78gs750]

wrg the fin, I have repaired one with jb weld, shaped with a file then painted over, no one will know....as to removal, patience....

[Drybear]

I had the same problem and it ended up like this!
I tried everything you mentioned but without any success..

[Rich82GS750TZ]

I had the same problem and it ended up like this!
I tried everything you mentioned but without any success..

Um, yeah.....I'm thinking that JB Weld probably isn't gonna help you here

[748cc]

I guess what you're telling us is that the engine is held together with 'Elmer's Poo'?

Sorry, couldn't resist. Also sorry, but I have no suggestions in freeing the cylinders from the case.
Perhaps there's a chemical used in farming or RV communities to break down 'solid wastes'?? But then,
What would they do to soft metals...hmmmm. Just keep paitence & work as thou it isn't urgent. Your
temper is what will break things, so remain cool calm & collected.

[Brendan W]

Yep, temper is what does the damage.
I'd be inclined to get a rope or strap through that cooling hole in the barrel between the cylinder and the chain tunnel and then hang the motor by it and start tapping some on the cases with a rubber mallet and let gravity and time do some work.

[sharpy]

Its stuck on the 2 dowels that locate the barrel to the cases AND what i presume is the genuine gasket.. Hitting it sideways wont do much. hitting it upwards at say 45 degrees be better. Spray/soak the bolt holes and around the outside of the base gasket with WD40 and let it sit over night and try again. Hitting the back and front would work better as its shorter and not as long a area than side to side. Tapping around the strongest area will the the cam chain tensioner area. Plastic mallet would work best.

[roeme]

Maybe some tie-down ratchet straps, putting the two parts under constant pull-apart force, and repeated heat/cooling cycles.

Cycling is important. Also, Heat Gun/Butane are weaksauce, use propane, that's proper hot.

Ice spray could also help, though i wouldn't know where to apply in this particular case.

As previous posters said, mostly temper breaks things, be patient.

[Nessism]

Typically, the bottom of a vertical rib joining the fins together makes a good pry point since it spreads the stress over all the fins, not just one. In some cases you can use a block of wood under the bottom fin, striking the wood with a hammer or prying, again, focusing on the area under one of the vertical ribs. Unfortunately, this method would not be possible on the side of the cylinder shown in the photo, but hopefully there is another side of the cylinder where this would be possible.

One other thing you may try is to hammer a block of wood wedged into the cam chain tunnel. This will create a moment trying to rotate the cylinder from the top. Can't go to hard at this approach though because the dowel's may damage the block/case.

[chef1366]

Its stuck on the 2 dowels that locate the barrel to the cases AND what i presume is the genuine gasket.. Hitting it sideways wont do much. hitting it upwards at say 45 degrees be better. Spray/soak the bolt holes and around the outside of the base gasket with WD40 and let it sit over night and try again. Hitting the back and front would work better as its shorter and not as long a area than side to side. Tapping around the strongest area will the the cam chain tensioner area. Plastic mallet would work best.

This
but with penetrating oil such as PJ Blaster

[Drybear]

20181031_201422.jpg
In my case it was the studs that were completely married to the aluminum block.
Impossible to release in one part.

[Argee]

It gives me great pleasure to announce..............I got the blinking thing off! :-D

cylinderstud.jpg

I tried lots of cycles of heat and plastic hammering and penetrating fluid but that didn't work at first. What made the difference was the 'drilling'. I didn't have a drill bit long enough to fit down the side of the stud and reach into the corrosion. I used numerous lengths (because they kept breaking) of 1mm stainless steel welding wire. I fitted the lengths (one each time) into the flexible head of a Dremel-type rotary tool. I tapped the end of each 'bit' with a hammer to flatten it a bit and provide a bit of a cutting surface.
Eventually (after spending several hours for several weekends...) I managed to remove most of the corrosion from around the base of the stud - then after a bit of heat-gun heat and a little tap with a plastic hammer it separated from the crank case.
I had to work a bit to get the cylinder body over the threads at the top of the stud - I effectively had to unscrew it. (I had taken all the other studs out.)
The only problem is that it's only January and I think I have used up most of my 2019 allocation of patience! ;-)

[Argee]

A photo of the hole...

cylinderstudhole.jpg

[Gorminrider]

Congratulations! Hope the project is a breeze from here on! I'll take it that any actual barn finds warrant a jaundiced eye with regards to ever getting them apart!