Author Topic: CB750 Crank Primary Teeth Worn - OK to Use?  (Read 3250 times)

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Offline rickman750

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CB750 Crank Primary Teeth Worn - OK to Use?
« on: December 27, 2014, 09:53:30 PM »
My cases are split, and we're in to scoping out the state. We've found the teeth on the primary drive sprocket are worn.

And now to my question - Is it usable? Or am I in for a replacement.

http://www.glasson.org/Pictures/nic750/Crank_primary_teeth.jpg

Offline goldarrow

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #1 on: December 27, 2014, 10:04:37 PM »
I would replace
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Offline Retro Rocket

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #2 on: December 27, 2014, 10:10:10 PM »
Yes, I wouldn't use that at all...
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #3 on: December 27, 2014, 10:35:11 PM »
Yes, I wouldn't use that at all...
Mick, you know where to get a good one in Oz? I'm doing the job.

Offline Retro Rocket

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #4 on: December 27, 2014, 11:01:07 PM »
Yes, I wouldn't use that at all...
Mick, you know where to get a good one in Oz? I'm doing the job.

A replacement crank..?  I'll ask around Nic, I know a guy that may just have one..... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #5 on: December 27, 2014, 11:13:13 PM »
Yes, I wouldn't use that at all...
Mick, you know where to get a good one in Oz? I'm doing the job.

A replacement crank..?  I'll ask around Nic, I know a guy that may just have one..... ;)
Appreciate it Mick, this engine needs everything, hadn't factored in a crank but when I found the primary chain tensioner was held in by about 3 threads and flapping around in there I wasn't surprised when I saw the state of the teeth. Someone has been in there, I found other loose bolts in the cam area as well.

Offline Retro Rocket

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #6 on: December 28, 2014, 12:29:28 AM »
I've made a couple of phone calls, no luck yet, i'll keep trying though... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #7 on: December 28, 2014, 01:10:55 AM »
Thanks Mick, they have plenty in the states but $200 shipping ::)

Offline Retro Rocket

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #8 on: December 28, 2014, 01:59:18 AM »
Nic, you are in Sydney aren't you..?  Try giving these guys a ring, they do hot Honda engines and may just have a crank lying around...I'll keep looking... ;)

http://www.robinsontoolmakers.com.au/big_bore.htm
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #9 on: December 28, 2014, 03:10:07 AM »
I'm closer to Canberra mate but I'll give em a ring, thanks, I'll let you know how I go.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #10 on: December 28, 2014, 05:54:01 PM »
Replacement crank acquired, thanks Mick for your help.

Offline Retro Rocket

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #11 on: December 28, 2014, 06:55:32 PM »
Replacement crank acquired, thanks Mick for your help.

Excellent... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline SOHC4 Cafe Racer Fan

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #12 on: December 28, 2014, 07:07:01 PM »
GREAT!!  ;D
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

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Offline 750cafe

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #13 on: December 28, 2014, 07:54:01 PM »
WTG Retro!  :D

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #14 on: December 28, 2014, 08:21:36 PM »
Ah yes well, actually, the crank was got from, ebay in the states.

Offline 750cafe

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #15 on: December 28, 2014, 08:23:50 PM »
He tried to help anyway.  ;) :-[
How much/little did you have to shell out for it with shipping?

Eric
Is there anything more fun than riding? They are between your legs and are quiet when you turn them off.

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #16 on: December 28, 2014, 08:42:17 PM »
He tried to help anyway.  ;) :-[
How much/little did you have to shell out for it with shipping?

Eric
Too much.

Offline rickman750

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #17 on: December 28, 2014, 11:55:58 PM »
He tried to help anyway.  ;) :-[
How much/little did you have to shell out for it with shipping?

Eric
Too much.
Seventy bucks........US........Plus shipping.

Now I'm worried about the big primary sprocket on the tranny input shaft......

Nic

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Re: CB750 Crank Primary Teeth Worn - OK to Use?
« Reply #18 on: December 29, 2014, 12:26:43 AM »
He tried to help anyway.  ;) :-[
How much/little did you have to shell out for it with shipping?

Eric
Too much.
Seventy bucks........US........Plus shipping.

Now I'm worried about the big primary sprocket on the tranny input shaft......
Worry not, I have inspected.