Topic: CB750 cylinder sleeves interchangeable in all years SOHC?

[Dresda500]

I have a customer with a std 61mm bore with one that dropped a valve and scored the cyl, so thinking to just swap out a stock liner and replace piston. can a later 77-78 F liner work in a ealry K cylinder ? Both are 61mm bore but unsure of the rest of the interface?...or anyone have a liner they would sell me?

[Dresda500]

CSMNL shows same part number for complete cylinder from '73 to '78.

[PeWe]

The sleeves from CB750 K3 are made for cylinders with wider oil returns. Those sleeve flanges are part of the hole.

EDIT: Yamiya say from  K4 when cylinder  got wider return holes.

They have both types of sleeves, scroll down. $$
https://www.yamiya750.com/index.php?main_page=index&cPath=246_21_249_54&sort=20a&page=2


If using that in an early cylinder those part of the holes will be seen.
Early sleeve in late, forget the oil return dowel pins if not milled by the shop.

[HondaMan]

LA Sleeve sells new liners, but not machined for the later oil drain dowel seals. They are $100 each from California, USA.

However: merely swapping liners will not make a good piston ring seal: since the piston clearance must be NO MORE than 0.0012" (and I routinely build them to about half that much) then installing an already-used liner will only make for an odd-shaped hole where clearances are involved. It will then burn oil.

It would be much less expensive to replace all 4 pistons with a set from someone like CrusinImage, in an oversize like 0.5mm. Use 0.0008" piston clearance AFTER honing and it will be stellar.

Note also: now that the engine is apart and you're about to use a modern head gasket to put it back together, you MUST deck the cylinders by 0.010" to restore quench banding and make the 2 oil passages at the back of the cylinders seal, because all modern head gaskets are now 1.0mm thick, or 0.010" thicker than those Honda used (no asbestos was allowed after 1996, hence the change), which were originally 0.8mm thick. None of the gasket kits take this into consideration, so they supply the normally-sized O-rings: this means the 2 O-rings thru the head-cylinder gasket will not seal, either. The OEM O-rings were 2.4mm thick: you must use 2.6mm thick in their place to prevent the leaks. Parker makes one in 10.8x2.6mm, their # 02-111.

[PeWe]

EDIT:
Bore all to a size that cover the scores.
If deep CI 836cc 65mm or a little less.
Tight fit as CI pistons needs
 More power

I have seen head gaskets that are 1.2mm thick. Hopefully compress to 1mm.
About sleeves.

I found a cheap cylinder with rusty 2-3 sleeves.
I was sure that 61.50 mm pistons should work. The guy boring saw rost pits so those  sleeves had to be replaced.
Bought from a friend for $30US each.
I should have ordered +1.0mm CI pistons

So if you find an extra cheap cylinder with damaged fins and rusty bores you take sleeves from,  +1.0mm pistons.

My shop did not charge much or anything for sleeve replacement.
He did it quickly, probably with a blow torch.