Author Topic: Splitting the cases on my CB750...first of many ?'s  (Read 83095 times)

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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #200 on: December 26, 2009, 04:44:13 PM »
Thanks guys...I'll be happy when the nice works actually works!  My helping hands are suppose to come over tomorrow to lift the engine back into place...wish us luck...any tips pls let me know...will keep all posted and surely will put a pic up if...er, when we are successful.
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Offline mystic_1

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #201 on: December 26, 2009, 05:17:20 PM »
Wrap the frame tubes with pipe insulation, cardboard, whatever, to prevent scratches when reinstalling the motor.

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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #202 on: December 26, 2009, 07:47:40 PM »
Thanks Mystic...just wrapped the pipes in cardboard...I'm sure that saved some repaint work.
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Offline KB02

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #203 on: December 27, 2009, 07:50:01 AM »
Mt dad and brother came over yesterday and we got my engine back in (gotta love the holidays). Three hands are better than two. But two hands are still way better than just one!  ;D ;D ;D
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #204 on: December 27, 2009, 07:13:34 PM »
+1...mine's in...here's the pic after installation and crash bars installed...lots of work still to do obviously



« Last Edit: December 27, 2009, 07:16:53 PM by ron.cieri.313 »
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #205 on: December 31, 2009, 02:51:56 PM »
Well, the rebuild continues...the exhaust, as usual, gave me a good fight..still have left side to put on but now I at least know the drill.





Waiting on the swingarm to be powder coated (satin black), and this time I'm sending the brass bushings and new collar to someone who knows what they are doing (I should've waited for Hondaman but the dealer did a decent job pressing them in for my 450)

After the exhaust and swingarm and rear wheel and new chain, I'm not sure what to do next in terms of order.  I think timing (check gap), battery (so I can do static timing)...then either clutch or carbs?  Carbs, I think, and then I can siync carbs with gas tank off to the side but flow attached...can I do this with the clutch off?...I think so...well at least until I see oil flow from the clutch axel port...then I can reassemble clutch and continue syncing carbs?

What do you guys think?...thanks!...ron
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #206 on: January 03, 2010, 02:26:46 PM »
Well, my winter vacation ends today so just a few pics to see where I'm at...finished re-timing (yes, the electric power is back!) and have the exhaust completely on...next week hopefully I'll have the rear end back together...and then carbs, and clutch...fingers x'd.



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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #207 on: January 11, 2010, 06:45:16 AM »
Fyi...another rebuild update...rear end is back together...except for that blasted master link clips (any tips are greatly appreciated).  The swingarm has been powder coated satin black (for $50 I couldn't complain about satin versus gloss)...new brass bushings have been press in...she fits in the frame snug as bug.  At first, I forgot to put the dust covers of the swingarm bushing and I'm like WTF?! y the big gap, then found the missing parts...geez its been a long slog...I notice my first post was on Sept. 28th...phew.

Leftover to do's include...aforementioned master link clip, lubricate chain, adjust lower throttle tension at the carb end (having trouble...tips once again appreciated)...set up gas tank on remote stand or bikes seat so I can test start and check oil flow through clutch, put on clutch, sync carbs and put on gas tank.  Well, I remember when the list was so long I couldn't even right it up.  BTW...with the wheel, I can rotate the tire while clicking through the gears by hand...it seems like a go...but ya' never know.

ttyl...ron






Also, had missing  buttons replaced on the seat back...$20...what a deal!

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Offline nobody

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #208 on: January 11, 2010, 09:36:50 AM »
I knew you'd finish before me Ron. My engine is still on the bench with the cases split. I finally got my Vesrah gaskets the other day and intend to start reassembly soon.
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If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #209 on: January 11, 2010, 11:49:24 AM »
Whose finished?...not till the tranny works with me riding the bike do we call this one finished...don't wish the arse rape fairy back to michigan....what gaskets are you waiting on?...i mean, for where?
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Offline nobody

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #210 on: January 11, 2010, 04:06:45 PM »
Hahaha, may the fairies stay at bay, I'll cross my fingers.

I just needed gaskets for the oil pan and side covers, I have the full engine kit sitting on the workbench. I've just been too distracted as of late to do anything about it. Need to get some Hondabond though, I'll probably stop by my local motorbike store on Saturday and grab some. Everything went smooth when I did the open case assembly, all of the forks enganed all of the gears, so I think we're good there.

While you may not be finished just yet, I'm trailing too far behind.
74 cb750k

If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #211 on: January 13, 2010, 06:52:55 AM »
No pics but a quick bit of news...the beastie STARTED yesterday...k, i know its not as could as the transmission working which was the whole point of this but still it felt good to hear her start up.  I don't know if its just been so long or she really did sound great, but she sounded great...at least to my ears.

...and I did have oil flow through the primary shaft to the clutch...which was one of the past problems on this bike.  So now, I can rebuild the clutch (I've done this several times so I feel pretty good about that), sync the carbs and maybe just maybe if the weather breaks a little in the next week...i can give her a quick test spin...if that tranny works, i think i'll cry, if it doesn't, I'm going to cry and start drinking.

Oh yes, I laid clean paper down under the bike after her test start so i could see if the seams were holding...so far, no visible leaks...l8r...ron.
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Offline Henning

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #212 on: January 13, 2010, 12:32:13 PM »
Isn't that just the sweetest part of a rebuild, hearing it run again!

Good work, Ron.

Me, I'm going through the carbs. After that I may take a look at the oil pump, or fit those tapered steering head bearings I have lying about. Can't ride anyway, there's ice and snow outside.
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #213 on: January 16, 2010, 10:06:57 PM »
I knew it...arse rape fairy.

I started a new post while this one was down but here's the deal...she's slipping in second...classic bent shift fork symptoms but how can this be?

I definitely have all my gears and she running fine...backfiring a little rough at time but I haven't sync'd the carbs yet which should take care of that.

I'm at a loss...I'm going to readjust the shift lever down a bit hoping I'm just not kicking her up hard enough into second gear.  Will also play around with the clutch adjustment...I do have the double center metal disc in the clutch so of course could always rebuild the clutch for the 90 time.

I'll take a pic...the bike looks great...dunno...maybe i'll just ride her with her slipping out of second.

as always...puhleaze give me ur suggestions...I haven't started drinking...yet.
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #214 on: January 17, 2010, 08:53:50 PM »
Okay, I'm off the ledge.  Here are the pics I promised...she looks nice i think, if you don't mind driving a bike with a very short second gear...funny, she doesn't seem to pop out gear into a false neutral when I engine break from 3 to second...
...any clues on to islolate the cause of this problem are greatly appreciated...I guess its rebuild the clutch time with a different setup or go back into the, gulp, cases.

I'm also dripping oil now from the back left of the crankcase, if fact I thought it was the oil feed through the shaft of the drive sprocket...I plug that up with hi temp gasket goo and still have the dripping...maybe its the oil seal behind the sprocket?

...help is always appreciated...I brought out my 450 into the work space as i feel i need a break from the 750...but won't give up...yet...thx.



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Offline ekpent

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #215 on: January 17, 2010, 09:11:47 PM »
Dang Ron as a MICH-Guy I have been watching as others and am sorry if you are haveing problems.Is it "popping" out of 2nd  again as you accereralate or just slipping??  Eric in Kazoo

Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #216 on: January 18, 2010, 04:25:51 PM »
Hi Eric..thx, the commiseration helps somehow...whats happens is...I'm in first, and it goes it 1st smoothly, no cluck, just a nice smooth, shift...same thing up into second (and really all gears...which I've confirmed are there)...so, first up into second, I let out the clutch and start to accerlerate, she stays in second for anywhere from a second or two or 5 or 6 and then, pops or slips into a false neutral (I'm not really sure what terms to use...falls might be a good description cuz its like when you fall into a short gopher hole) and then I pull in the clutch shift into 3rd no problem and so on up as needed.  I engine brake alot and it doesn't seem to slip or fall out of second gear then but I'm moving into first anyhow at that point. Take more time to fall out second when its cold but that is really conjecture at this point as I haven't done enough test drives.

I've sync'd the carbs just for yucks at this point and she runs nicely...all new rubber and brakes.  I could try messing around with the clutch but would like to hear opinions if that is possibly the problem or just wishful thinking.  The oil I used in the Honda 10W - 40.  I know it points to a bent shift fork but they I fork I put in looked good to the naked I...it was a replacement bought of ebay...in fact I replace the shift drum and forks.

What do peeps think?...I thought this post was ending, and as somebody mentioned...when that day comes I'll be very very very very happy...but till then, need your ideas...thanks...ron.
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Offline nobody

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #217 on: January 18, 2010, 04:53:00 PM »
I can't help feeling like my premature congratulations brought this on. That sucks, Ron, I'm really sorry to hear this.
74 cb750k

If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #218 on: January 18, 2010, 04:57:50 PM »
Lol...yes, we always need a scapegoat.
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Offline nobody

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #219 on: January 18, 2010, 04:58:27 PM »
I'll take the blame. How could I be such a bastard?! DAMN ME!
74 cb750k

If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #220 on: January 18, 2010, 05:07:44 PM »
Youthful exuberance ;)
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Offline nobody

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #221 on: January 18, 2010, 05:12:50 PM »
Haha, well best of luck to you man. I've no insight to offer but hopefully somebody else can sort you out without the need to pull the motor again.
74 cb750k

If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline mystic_1

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #222 on: January 18, 2010, 11:00:27 PM »
Hi Ron.

Sorry to hear about your 2nd gear issues.  Look at it this way, at least your symptoms are different from your original Oil circulation problem?...getting hung up in neutral thread.  That means you've made progress!  OK enough cheerleading :D let's see what we can figure out.

Popping out of second is a fairly common issue with the 750, it's one of the first signs of transmission problems.  It's common enough that people frequently have their transmission gear dogs undercut in order to prevent this problem.  Ron (MCRider) had this done, he has some nice pics in his build thread.

Shifting from first to second involves movement of the C5 gear (see pic below) and is done by the leftmost shift fork as viewed from above.  The reason it's popping out is often because the shift dogs on C5 don't fully engage into the slots on C2, and C5 pips back to the left a bit under pressure resulting in your false neutral.

The odd thing here to me is that after this has happened, lifting on the gear shift lever usually puts you back into 2nd gear.  From your post, when you do this you end up in 3rd.  So, I suspect that your problem is actually "overshifting" wherein when you shift from first to second, the shift drum rotates too far and you end up just slightly PAST second gear, in other words, C4 is partially shifted.

I'd start by removing the shifter cover (aka "mission cover") on the left side of the engine and then working the shifter as you observe the end of the shift drum.  The little bits around the shift drum (positive stopper assembly) are supposed to control the action of the shift drum so that it stops in the right positions.  Your problem may be there somewhere.

hope this helps

mystic_1
« Last Edit: February 01, 2010, 01:04:10 PM by mystic_1 »
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Offline ron.cieri.313

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #223 on: January 19, 2010, 08:10:41 AM »
Hope springs eternal..thx Mystic...I wonder if I put the pins back in the correct place or some other assembly error here with the shift mechanism...hmmm, this is definitely where I will start.

If it is an "overshifting" issue, would that also fit the fact that when I down shift during engine braking from 3rd to 2nd, it does not slip at all?

And, one more question, can I rule out a clutch issue as it only happens in this gear...some one kind enough to respond to another of my post said that if it was a clutch problem, the slipping would be more pervasive in all gears...makes sense...is that true?  At least it stops me from rebuilding the clutch...again.
« Last Edit: January 19, 2010, 08:12:54 AM by ron.cieri.313 »
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Offline mystic_1

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Re: Splitting the cases on my CB750...first of many ?'s
« Reply #224 on: January 19, 2010, 08:53:24 AM »
If it is an "overshifting" issue, would that also fit the fact that when I down shift during engine braking from 3rd to 2nd, it does not slip at all?

I think so, if you observe the mechanism while shifting up and down, you'll see that shifting up uses one end of the shift armand shifting down uses the other end.  Also up-shifting into a gear involves different shift fork movement than down-shifting into that same gear.


And, one more question, can I rule out a clutch issue as it only happens in this gear...


Well, I don't know that you can rule it out completely, but yes I agree it sounds unlikely given your symptoms.  It's always possible that a dragging clutch is exacerbating things, but I would address the shift mechanism first.

mystic_1
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