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Author Topic: Cb750 Crankshaft identification  (Read 568 times)

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Offline bustech51

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Cb750 Crankshaft identification
« on: March 18, 2022, 02:33:29 PM »
I just got a call from a friend who is rebuilding a 1974 cb750 for a customer.  The customer would like a completely original engine if at all possible.  My friend is looking for a crankshaft for the engine.  I have 6 standing up that are good.  As far as I  know they will all work but is there any way of differentiating which year they are from.  Stamping numbers, casting alpha/numeric codes??????
Help a guy help a friend.

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Offline bryanj

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Re: Cb750 Crankshaft identification
« Reply #1 on: March 19, 2022, 12:55:29 AM »
Not to my knowledge
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Offline Don R

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Re: Cb750 Crankshaft identification
« Reply #2 on: March 19, 2022, 07:16:44 PM »
 The one in the middle is the K4. I'm just sure of it.
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Offline scottly

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Re: Cb750 Crankshaft identification
« Reply #3 on: March 19, 2022, 07:25:37 PM »
Quote from: Don R on March 19, 2022, 07:16:44 PM
The one in the middle is the K4. I'm just sure of it.
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Offline bustech51

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Re: Cb750 Crankshaft identification
« Reply #4 on: March 19, 2022, 09:19:43 PM »


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Offline PeWe

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Re: Cb750 Crankshaft identification
« Reply #5 on: March 19, 2022, 11:57:02 PM »
I should go for a crank with good journals, sizes matching the case with bearings.

Good rods with bearings hopefully assembled too. Later assemblies have the better rod bolts with collar nuts.
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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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