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Author Topic: CB750 K4 crankshaft regrind. Need to source new main and big end shells  (Read 914 times)

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Offline Joe Hill

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CB750 K4 crankshaft regrind. Need to source new main and big end shells
« on: February 04, 2021, 04:37:31 PM »
Hello all. My 750/4 needs a crankshaft regrind so I need to source oversize main and big end shells. I am in Australia. Any help much appreciated
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Offline BPellerine

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Re: CB750 K4 crankshaft regrind. Need to source new main and big end shells
« Reply #1 on: February 04, 2021, 05:30:51 PM »
you do not grind the crank on the cb 750,just fit new shells,if the crank is good,if not source another crank
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Offline Don R

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Re: CB750 K4 crankshaft regrind. Need to source new main and big end shells
« Reply #2 on: February 04, 2021, 05:36:31 PM »
 The 4 bearing sizes are all stock and within a few ten thousandths so there is not enough room to allow grinding. As far as we know no one has ever found oversize bearing shells.  Hopefully your crank will polish up.
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Offline johno

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Re: CB750 K4 crankshaft regrind. Need to source new main and big end shells
« Reply #3 on: February 05, 2021, 01:35:17 AM »
Hi Joe,
There was a company in Australia that used to make oversize bearings for the 750 Honda, it was ACL. As far as I am aware they stopped production a long time ago but I did see two sets advertised on Ebay about 2 years ago so you never know what you may find with some luck.  The longest shot may be google up ACL and see if they have old stock.
cheers Johno
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Online PeWe

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Re: CB750 K4 crankshaft regrind. Need to source new main and big end shells
« Reply #4 on: February 05, 2021, 06:52:24 AM »
Might be cheaper to find another crank in good shape with rods.

Get this good looking one for a lower price


https://www.ebay.co.uk/itm/353372427419
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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967
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