Author Topic: Cylinders stuck. Need Help!!  (Read 1078 times)

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Offline KB02

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Cylinders stuck. Need Help!!
« on: April 06, 2011, 04:34:03 AM »
Hey Gang. If you have seen my other thread you know that I am doing some engine work on my wife's 1978 CB400T. I need to replace the cylinder base gasket and have gotten the bike torn down almost to that point, but I can't get the cylinders off. The buggers are stuck like you wouldn't believe. The only thing I have manager to do so far is take some nice chunks out of my rubber mallet.

Any suggestions?
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

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Offline chickenman_26

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Re: Cylinders stuck. Need Help!!
« Reply #1 on: April 06, 2011, 08:37:43 AM »
It might be stuck on the gasket, or the dowels in the rear corners may be stuck in the cylinder. Put a block of wood between the crankcase and the stub on the backside of the cylinder where the cam tensioner locknut was. Then use a bar between the wood and the stub to lever the cylinder loose. Once you get it to crack open a bit there, spray WD-40 in the gap to help loosen it all around. Keep wiggling the cylinder as you spray, and have patience.

Stu
MCN DTF

Offline crazypj

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Re: Cylinders stuck. Need Help!!
« Reply #2 on: April 06, 2011, 12:04:14 PM »
They used to stick when 'new', it's got vulcanising gaskets with heat activated sealer.
 It's a load of fun to remove cylinders without breaking anything.
 Try a safety razor blade and 'split' the gasket as much as possible before beating it with sticks  ;)
 Late 70's/early 80's Honda's were never meant to come  fully apart, (clutch and generator covers come off reasonaby easy and cam cover has rubber gasket)
 I'm almost surprised Honda didn't JB Weld the cases together  ;D
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Offline KB02

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Re: Cylinders stuck. Need Help!!
« Reply #3 on: April 06, 2011, 04:26:32 PM »
I'm almost surprised Honda didn't JB Weld the cases together  ;D

I'll almost be surprised to find that it isn't.  ::)
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline crazypj

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Re: Cylinders stuck. Need Help!!
« Reply #4 on: April 06, 2011, 10:32:54 PM »
I'm almost surprised Honda didn't JB Weld the cases together  ;D

I'll almost be surprised to find that it isn't.  ::)

 I only just remembered
They Araldited the case together on the race bike's, remember seeing an article about it probably 20+ yrs ago when Redman's or Hailwood's  bike was being restored
« Last Edit: April 06, 2011, 10:35:02 PM by crazypj »
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Offline KB02

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Re: Cylinders stuck. Need Help!!
« Reply #5 on: April 11, 2011, 03:53:54 AM »
Finally got the cylinders off. A 1"x1"x1' piece of PT wood and a sledge hammer finally did the trick and didn't break any fins.  ;D  Heat was the next thing to try, but it looks like I won't have to go that far.
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline chickenman_26

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Re: Cylinders stuck. Need Help!!
« Reply #6 on: April 17, 2011, 07:40:43 PM »
Finally got the cylinders off. A 1"x1"x1' piece of PT wood and a sledge hammer finally did the trick and didn't break any fins.  ;D 
Glad to hear it. Now you can spend the next three weekends removing what's left of the old base gasket.
MCN DTF