CB750K2

[Steve Evans]

Hi all, I just purchased a Cb750K2 with a K5 engine. If I find a K2 crankcase can I transfer bottom end/transmission fromK5 into the K2

 

[dirtdigger]

Yes but there is really no need to unless all you want is the correct period number, the cases are the same. You will have to check and will have to install the appropriate main bearings when you do the swap.

 

[Steve Evans]

Thanks, yes I wish to bring it back to original. all I need is someone in Australia with a K2 crankcase for sale

 

[dirtdigger]

It still wont be 100% a k2 with just the cases. There are other differences, especially on the inside of the motor that a purist will know are not right. Casting numbers on the head and cylinder block will be different as well as the shifter side cover and oil line markings are different. A fair amount of internal parts changes/improvements went on in the couple years between k2 and k5. The real K2 did make a bit more power then the K5. If you really want it to be original then all of it will need to be changed for correct parts which then leads to the point of why? If you want an original k2 then you need a real K2 motor to put in it. K2 cases only make your motor an original k2 cased motor which really doesn't have much meaning, just dont try to sell the bike as all original with just the case swap...someone might call your bluff if they really know what to look for. But hey, its your bike do what YOU want