Author Topic: Can't get these CB750 cases apart  (Read 1202 times)

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Offline mycb750k6

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Can't get these CB750 cases apart
« on: January 19, 2011, 08:26:10 AM »
Going dumpster diving in this old motor for parts once I get it apart but I'm having trouble doing that. I've removed all the bolts I'm sure. Can't get it to crack open though. Is there a pry point somewhere?

Offline SOHC Digger

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Re: Can't get these CB750 cases apart
« Reply #1 on: January 19, 2011, 08:40:06 AM »
There's not really a pry point, just several strategic places to strike with a plastic or rubber faced hammer.  The sealing bond and the dowels do such a good job holding the cases together that you just have to go round and round tapping on the edges where the mating surfaces don't fit flush.  Inside the clutch housing is a good area to start.

Offline Shoeboxjoe

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Re: Can't get these CB750 cases apart
« Reply #2 on: January 19, 2011, 08:43:20 AM »
I think i used a paint scraper to start opening the case around the points. Crack the front seam and open the cases like a clam shell being careful not to pry too much on the mating surfaces for obvious reasons.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Can't get these CB750 cases apart
« Reply #3 on: January 20, 2011, 12:05:42 AM »
Myles,

I tapped the rear with my rubber mallet. There should be a place or 2 that overlap.
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Offline ekpent

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Re: Can't get these CB750 cases apart
« Reply #4 on: January 20, 2011, 09:44:47 AM »
I also think that there is an area that has kind of a flat tab section at the rear of the crankcase that may be considered a gentle "pry" area.

Offline 754

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Re: Can't get these CB750 cases apart
« Reply #5 on: January 20, 2011, 10:38:53 AM »
 Check starter cavity. may be a missed case screw in there..

 No reason ever to pry anything apart at the seam or join.. cept maybe to prove you are a dumbass..

 There is aways another safer way, the only time , it is real tricky is seperating head from cylinder if you are trying to keep barrels on and base gasket intact..
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Offline Elan

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Re: Can't get these CB750 cases apart
« Reply #6 on: January 20, 2011, 10:53:58 AM »
I had to prop up half with a 2x4, and slowly pulled the other half toward the table.. Just enough to get it moving.

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Offline 754

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Re: Can't get these CB750 cases apart
« Reply #7 on: January 20, 2011, 11:15:29 AM »
Too much work..
 To get it started, put 2 bars or bolts in rear motor mounts, now between them, use a 2x4 and a wedge, or a pce of reddi-rod, with a nut on either end, then turn the nuts to spead ot (ie, jack it gently apart. Try clutch side, the long mount on chain side, could break with too much force..

 When one end goes, the rest is easier..
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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 markb

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Re: Can't get these CB750 cases apart
« Reply #8 on: January 20, 2011, 12:27:45 PM »
Too much work..
 To get it started, put 2 bars or bolts in rear motor mounts, now between them, use a 2x4 and a wedge, or a pce of reddi-rod, with a nut on either end, then turn the nuts to spead ot (ie, jack it gently apart. Try clutch side, the long mount on chain side, could break with too much force..

 When one end goes, the rest is easier..
I like that idea.  :)
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