Topic: How do I remove seized Barrels

[Keith61]

Hello . New here so hope this is in the right place.
I have an old CB550 which I have great plans for , first of which is to strip and clean the engine.
The problem I am having is that I cannot get the barrels off the casing. When removing the nuts from the engine studs all came off except for the stud at the front between cylinders 2 and 3 which sheared easily as it was heavily corroded. I have managed to get movement around the base apart from an inch or so either side of this stud which won,t budge. I have tried hitting with a mallet to loosen . When it was in the bike I fed a rope through the stud hole and used a lever over the frame to pull up. No joy. Now it is on the bench I have fed a nut through the fins threaded a bolt trough it down the stud hole and on to the end of the remaining stud  and used this to try and lift the barrels again no joy . All with regular soakings of WD40 and beatings with the mallet. If anyone has had a similar problem any help would be greatly appreciated as I am now out of (limited) ideas .
Thanks .....Keith

[Davidov]

The pistons are seized in the cylinders?

Or do you mean that the cylinder assembly won't come off of the crank case?

http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=360001

[flybox1]

be careful not to break fins
remove all studs
one trick is to fill cylinders with 50/50 atf/acetone mixture and let it set for a few days, refilling as needed.
this will get the atf in past the rings and loosen it up.
 

[calj737]

Try rotating the crank using the bolt under the stator, NOT under the points cover. Agree, your pistons sounds as though they're hanging up the cylinders. Plenty of penetrating oil in the cylinders, rotate the crank, and continue to pry the jugs up.

If not, the other proven method is to bolt the head to the jugs, stuff cotton rope in the chambers, then rotate the crank. The rising piston will push the cylinders up with head attached to it.

[Keith61]

OK Thanks. Pistons are free in the bores , the barrels are just stuck to the top casing around the broken stud. Using the pry slots either side I can see slight movement it is just solid round this stud. Have a slight problem with the rope in cylinder idea in that the 6mm bolt on the front of the barrel has also sheared so I will have to get that out first

[Rocky2010]

Interesting read referring to the fire in the hole for a seized piston in the bore 

[rb550four]

Keith, I have  stupid questions, is the entire head is off right? I mean , you have an unobstructed view of all the pistons in the cylinders, right??
  If it is only that the barrels are stuck to the upper case why not some slide rachet straps (or wire) through the barrels and hang it from the rafters or the work bench so that the front of the motor is an inch off the floor and the lower rear mount is up on a 2x4 and let gravity and the weight of the tranny do the work... it's like a constant pull upwards on the jugs . Leave it hang for the night and see if that works for you.You can add more weight on the tranny, near the jugs if it isn't enough weight.
I've hung a few  stuck motors off the rafters out of the bike before but, had quicker results while it was done in frame and was able to use the weight of the rest of the bike to do the work. Low impact and you can do this in your sleep.

[Davidov]

Interesting read referring to the fire in the hole for a seized piston in the bore 

http://www.youtube.com/watch?v=MO1jjOSkpms&list=UUOm_dzAtaif27WLbbUOYCzQ
Seized pistons 

OK Thanks. Pistons are free in the bores , the barrels are just stuck to the top casing around the broken stud. Using the pry slots either side I can see slight movement it is just solid round this stud. Have a slight problem with the rope in cylinder idea in that the 6mm bolt on the front of the barrel has also sheared so I will have to get that out first

If your cylinder head is off, the cylinder assembly should lift off of the studs. The studs won't be holding it after that.

[rb550four]

If your cylinder head is off, the cylinder assembly should lift off of the studs. The studs won't be holding it after that.
 That's what I thought until I re read Keith saying the pistons were free in the cylinders.
 I have had a couple motors go through here where the studs were so corroded and crusty that they wouldn't break free easily , and it took some real work to slide the barrels up the rods. I suspect he could have run into a motor with the same problem.
  It'll be interesting to see what the problem really was.

[Don R]

 electric heat gun?

[Duanob]

Sure you got all the bolts? You could try tapping it with a rubber mallet but not too hard you might break the fins. They should come right off though. In fact the biggest problem with doing just the head is when you lift the head the jugs usually break the seal at the case unless you get really lucky like me 

[strynboen]

its happens the cylinders get stuck,,if the bike are in vet clima..my 400 four vas cylenders rusted together vith the pin bolts.and i vas not abel to lift the it off..have to made some vood brikks to put under the cilender block..and then hammer carefull to it got loose and heat it some..use avooden block to use the hammer on..

[setdog]

Could dowel pins be rusted and causing cylinder to stick to case?
Penetrating lube and wait it out?

[calj737]

Definitely flood the stud holes with penetrating oil, then apply heat at base where the dowels are located. A propane torch will not hurt the cases at all. Even might help separate the gasket in case someone previously used gasket glue 

[Keith61]

Thanks for all the responses . All bolts are out and everything is off that should be so I suspect it is corrosion holding this together. The bike is a do,er up off ebay and came with the engine caked in mud so I suspect it was put away dirty and stayed that way. For a long time !! Haven,t tried heat yet as I was worried it may warp the block if not heated evenly . I only have a small blow torch but will give it a go. I have heard that there are dowels around each stud . Is this correct ? .
Busy for a few days but will let you know how I get on

[flybox1]

remove the bottom case, flip her over, and pull out the crank/rods/pistons