Author Topic: The Cylinder Head just won't come off!  (Read 3418 times)

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Offline Romhog

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The Cylinder Head just won't come off!
« on: April 08, 2013, 06:00:51 AM »
Well, I'm glad I have the patience, but attempting to remove the cylinder head on my CB550 over the weekend felt like.... controlled violence ... but in the end, I can't get it removed!!
I sprayed  pbblaster and let it soke for about 3-4 hours and tried using various hammer and wedge techniques but just started getting nervous that I would crack it or mar up the head/block.

I think where the wind in my sails went limp was when I finally got the idea to setup a wedge point with 2 car jacks across the bike and a large steel pipe sitting on top of the them to make a "table" to wedge on.  ( the pipe sits though were the carbs would be) up as close as I could to the intakes and then took a  large crowbar and just about stood on the bar with my other foot on the foot petal to keep the bike from lifting off the ground, and then started hammering it as well with a 3 -lb hammer. and she just won't show signs of letting go.

I have the 2 flange bolts removed and all 12 bolts are either removed or (a few of them are turning the bolts with them but have enough room to at least free loose.) .  I tried a bit of heating up the gap as well but only for about 5 min around the block 2-3 times but nothing changed.

does anyone have another trick or idea I can try? I have a feeling the only method that will work is the hammer and chisel  but i hate hitting the block like that trying to get a wedge started.

thanks in advance!

Paul

Offline 754

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Re: The Cylinder Head just won't come off!
« Reply #1 on: April 08, 2013, 06:58:56 AM »
Do you have a manual? Iknow on 750 there are a few bolts everyone misses, if they do not use the book.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Romhog

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Re: The Cylinder Head just won't come off!
« Reply #2 on: April 08, 2013, 07:05:14 AM »
yeah I'm working right out of the Service Repair Manual. Not that it matters but you said 750 and my bike is a 550. I just had a weird idea but those bolts should be floating through the head not threaded correct ?? I've never seen bolt straight all the way through a cylinder head before but that's just me trying to think Of reasons :)
« Last Edit: April 08, 2013, 07:25:02 AM by Romhog »

Offline rb550four

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Re: The Cylinder Head just won't come off!
« Reply #3 on: April 08, 2013, 07:37:37 PM »
I've had this problem with seized 550's before, used to hang the motors from the rafters, then I found that leaving it in the frame offers more weight for pulling the jugs off



I set them up like this and it usually works overnight . Although I did have a really stubborn one once that
required a 1 1/4 overturned socket over a rag and an air chisel, hitting the chisel a few times on the socket to break the pistons free. The rag is very important , if you don't use one you won't be saving the piston. You just want to break the rings free and the head( that is tied to the rafters with the bike hanging) the bike will eventually slip downward and the jugs will be left suspended. Sorry about the crappy pics.      RB
« Last Edit: April 08, 2013, 07:41:53 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline rb550four

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Re: The Cylinder Head just won't come off!
« Reply #4 on: April 08, 2013, 07:51:28 PM »
Cylinder head, duh, if the cam and timing chain aren't out and  the 2 bolts under the cam covers,  aren't off , you can pull your ass off all day and it won't come. Please post pics of this pressure resistant engine so we can get a better idea of what's going on.    RB
« Last Edit: April 08, 2013, 07:55:09 PM by rb550four »
A few Honda 500's, a few Honda 550's, a few Honda 650's, '72 cb 450, a couple 500/550/650 hybrids, and 2001 750. 
  550 Snowbike -Somebody had to do it.
  http://forums.sohc4.net/index.php/topic,101678.0.html             
http://forums.sohc4.net/index.php/topic,137317.msg1550907.html#msg1550907

Offline 754

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Re: The Cylinder Head just won't come off!
« Reply #5 on: April 08, 2013, 07:58:19 PM »
If everything is off that should be,,make a fitting to put grease nipple into a sparkplug thread..then pump it into acylinder with closed valves.. Pump it off..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Romhog

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Re: The Cylinder Head just won't come off!
« Reply #6 on: April 09, 2013, 05:13:19 AM »
thanks for sharing the pics and taking the time to give me ideas.....
 I feel so bad and maybe heading home after 7 days strait of working  to tackle taking the head off the bike isn't a good idea  :) ...... but...754 hit the nail on the head..... I @#^@#^ forgot to get one of the nuts loose that I thought was one stuck to the bolt (but loose). turns out I just overlooked it 3 times.... 
head is off!

Offline lucky

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Re: The Cylinder Head just won't come off!
« Reply #7 on: April 09, 2013, 06:51:21 AM »
Happens 99% of the time.

Offline iron_worker

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Re: The Cylinder Head just won't come off!
« Reply #8 on: April 09, 2013, 09:18:23 AM »
Hopefully you didn't wreck anything while trying to jam wedges under it.... :o

IW

Offline Duanob

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Re: The Cylinder Head just won't come off!
« Reply #9 on: April 09, 2013, 02:07:48 PM »
Happens 99% of the time.

Yep to all of us!
"Just because you flush a boatload of money down the toilet, doesn't make the toilet worth more",  My Stepfather the Unknown Poet

1974 CB360T
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