twin cylinder barrel won't come off

Bert Reganze

Bert Reganze

Junior member
Location
Leiden NL
Tried to remove the barrel from my 1972 750SF, but it doesn't come off. The Green Book just mentions "carefully tap it with a hide-headed hammer", but doesn't where to tap. I tapped everywhere for more than an hour, nothing happens. It sits there for more than 15 years. Any advice would be great.
 
I had a similar issue last week and was directed to careful heat application around the base gasket. Used a heat gun and then tapped the barrel free with a rubber mallet.

HTH
Gerald
 
Using Paul?s method makes sense. A couple of pistons hitting the valves should help lift it. ::)

A bent valve or two will give you all the more reason to get the head off. :D
 
Often happens when the base gasket is installed with gasket goo, a true bastard to remove.  I've had to resort to hammering in knife blades to split the gasket.

You could refit the head using only the short outer studs and include a curled length of rope in the cylinder with closed valves.  Turn the crank to use the piston to force off the barrel.

piet
 
If I were you I would take your time , WD40 down the studs, leave overnight (Or as long as it takes  ) and try an air line down the studs. Soft mallet you have to be so careful. Softly softly catches monkey. Don?t hammer anything into the gasket it will end in tears.Jason
 
What's the WD40 down the studs supposed to do?  The stud bores are used to transport oil to the head and back down for the RH main bearing and oil seal, they're full of oil anyway...

The base gasket is tough, difficult to tear it apart if glued tight.

piet
 
chrisk said:
Using Paul?s method makes sense. A couple of pistons hitting the valves should help lift it. ::)

A bent valve or two will give you all the more reason to get the head off. :D
Click to expand...

The man said barrel. And I suspect that english isn't his mother tongue.

Paul
 
Like Piet.

I had to resort to this to split my 3C cases.
Also allows me to make sure that my wife's lovers are less appealing.

Paul
 

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sfcpiet said:
What's the WD40 down the studs supposed to do?  The stud bores are used to transport oil to the head and back down for the RH main bearing and oil seal, they're full of oil anyway...

The base gasket is tough, difficult to tear it apart if glued tight.

piet
Click to expand...
If you have been tapping the barrel ( as op has) and has moved the barrel Even ever so slightly the WD will find a path because it?s penetrating fluid, an air line will enhance the process. That?s what I would do.
 
sfcpiet said:
You could refit the head using only the short outer studs and include a curled length of rope in the cylinder with closed valves.  Turn the crank to use the piston to force off the barrel.
Click to expand...

If the rope trick doesn't work, perhaps make up a little manifold to pump compressed air into the spark plug holes (so long as valves are in but no camshaft - you want all valves to be closed). Maybe tie a rope over the head to stop the head/barrel assembly from hitting your workshop ceiling if it lets go at 100psi  :D
 
sfcpiet said:
Often happens when the base gasket is installed with gasket goo, a true bastard to remove.

piet
Click to expand...

no kidding! still haven't figured out what this grey, rock hard s*#t is. Real PITA to remove....
 

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Bert Reganze said:
Tried to remove the barrel from my 1972 750SF, but it doesn't come off. The Green Book just mentions "carefully tap it with a hide-headed hammer", but doesn't where to tap. I tapped everywhere for more than an hour, nothing happens. It sits there for more than 15 years. Any advice would be great.
Click to expand...
indeed, English is not my mothers language, sorry, but I didn't mention something about the head or pistons ::). So I removed the head, and that was also quite hard to remove, but a certain point the gasket breaked and the head came off. Now I want to loosen the barrel from the crankcase, but it sticks very hard. There is no problem with the pistons.
 
I would be trying the heat gun option, failing that a thin blade through the gasket. I have never needed to use gasket gunk on base gaskets on a twin but some people never assemble anything without it.
 
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