Author Topic: CB750 K1 Inner Countershaft Bearing?  (Read 404 times)

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Offline Lucien Harpress

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CB750 K1 Inner Countershaft Bearing?
« on: August 25, 2023, 02:26:06 PM »
I'm putting together the bottom end of a 1971 CB750, and somehow I managed to lose the inner roller bearing for the transmission.  This is the one that goes on the right side of the countershaft, the only non-grooved bearing that fits fully into the lower engine case, not sandwiched between the upper and lower halves.

https://www.cmsnl.com/honda-cb750k0-four-1969-usa_model14346/partslist/E18.html
(Part 21 in the link above)

I did my usual CMSNL search and came up with a part number of 91001-035-000.  However, when the bearing I ordered arrived, I found that while it fits on the transmission shaft, it's way too big to fit into the milled recess in the case.  I don't know if this changed on the later engines or what, and I'm only getting problems because my engine is so early.

Either way, does anybody know what the right size bearing I need for this is?  I'll try to figure it out in the meantime, but if anybody could point me in the right direction (or even just get the bearing number off a proper-sized bearing) I'd appreciate it.  Thanks!

-1970 CB750 K0
-1980 KZ1300
-1976 Yellow GL1000
-1965 CA77 "Dream"
-1997 Valkyrie
-1975 Velosolex

Offline HondaMan

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Re: CB750 K1 Inner Countershaft Bearing?
« Reply #1 on: August 25, 2023, 06:27:08 PM »
I'm putting together the bottom end of a 1971 CB750, and somehow I managed to lose the inner roller bearing for the transmission.  This is the one that goes on the right side of the countershaft, the only non-grooved bearing that fits fully into the lower engine case, not sandwiched between the upper and lower halves.

https://www.cmsnl.com/honda-cb750k0-four-1969-usa_model14346/partslist/E18.html
(Part 21 in the link above)

I did my usual CMSNL search and came up with a part number of 91001-035-000.  However, when the bearing I ordered arrived, I found that while it fits on the transmission shaft, it's way too big to fit into the milled recess in the case.  I don't know if this changed on the later engines or what, and I'm only getting problems because my engine is so early.

Either way, does anybody know what the right size bearing I need for this is?  I'll try to figure it out in the meantime, but if anybody could point me in the right direction (or even just get the bearing number off a proper-sized bearing) I'd appreciate it.  Thanks!


It should be part #96100-62040-00 (aka #96100-620-400 in the previous numbering system).
It is a standard 6204 bearing: in a pinch you might be able to get one from your local autoparts or bearing store, too. If you end up with one that has the seals on it then, they just pry off. I've done that before, around 2010 when Honda wasn't supplying these for a while.
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Offline Lucien Harpress

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Re: CB750 K1 Inner Countershaft Bearing?
« Reply #2 on: August 26, 2023, 07:36:20 AM »
Okay, that makes sense.  It looks like a mis-print on the parts diagram- I accidentally ordered the other side.

I've got a correct bearing on the way.  Thanks!
-1970 CB750 K0
-1980 KZ1300
-1976 Yellow GL1000
-1965 CA77 "Dream"
-1997 Valkyrie
-1975 Velosolex