CB72 or CB77 crank ?

cliquet · Post by **cliquet** » Sat Oct 26, 2013 9:45 am

hi
I am new on this site and need an answer.
I am restauring a "65" CB72. the crank is out of order . my question is :
does a CB77 crank and rods fit on CB72 motor? because numerous CB77 used cranks are sold on internet ;CB72 cranks are very rare .
thanks for answer
regards
Cliquet (France)

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Oct 26, 2013 10:12 am

The crank will install but it has a different balance weight when running than the 250.
What is wrong with your crank?. ............lm

cliquet wrote:hi
I am new on this site and need an answer.
I am restauring a "65" CB72. the crank is out of order . my question is :
does a CB77 crank and rods fit on CB72 motor? because numerous CB77 used cranks are sold on internet ;CB72 cranks are very rare .
thanks for answer
regards
Cliquet (France)

cliquet · Post by **cliquet** » Sat Oct 26, 2013 10:41 am

fast reply!! thanks LM
in fact I have changed the rods and rollers (big end side) and rebalanced the crank ;however the clearance rod (big end ) is not standard and I can ear the play (toc toc toc) ; so what can I do?:
- buy 2 new weight, Center (more than $200...)
- buy a used crank but plenty of CB77 and no CB72 ,hopping that clearance will be ok and problem of balancing as you told me....
thanks for your adviceLM
Cheers
Cliquet

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Oct 26, 2013 10:44 am

Are you sure it is the big end and not the small end? ..................lm

cliquet wrote:fast reply!! thanks LM
in fact I have changed the rods and rollers (big end side) and rebalanced the crank ;however the clearance rod (big end ) is not standard and I can ear the play (toc toc toc) ; so what can I do?:
- buy 2 new weight, Center (more than $200...)
- buy a used crank but plenty of CB77 and no CB72 ,hopping that clearance will be ok and problem of balancing as you told me....
thanks for your adviceLM
Cheers
Cliquet

cliquet · Post by **cliquet** » Sat Oct 26, 2013 11:02 am

Absolutely sure , LM ; the crank is on my table and I can move the rods and the big end .both are noisy , the right stronger . the little ends are perfect .
Cliquet

G-Man · Post by **G-Man** » Sat Oct 26, 2013 11:07 am

Did you measure the big end pins and rod when you had it apart?

G

cliquet · Post by **cliquet** » Sat Oct 26, 2013 11:37 am

No I did'nt.
in fact I bought the rods with rollers ;they were sold on ebay to fit CB 72,CB77.
I asked a specialist to replace rods and to balance the crank .
I must tell you that after riding ,the motor suddenly blocked .after ten minutes ,it started again freely but noisier... I am afraid the rod play is due to this incident..

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CB72 or CB77 crank ?

CB72 or CB77 crank ?

Re: CB72 or CB77 crank ?