Heya all, I’ve just commissioned a 350-4 1972 mode and
When servicing the engine I pulled the oil filter canister off and observed that the oil filter (std Honda, same as the 750’s) has an aluminum space about 1-5” long in what is otherwise an oversize oil filter canister. I read somewhere this was to increase the oil capacity of the engine. Both my canisters from 2 barn find bikes are damaged so I put an NOS CB750 canister and bolt on the engine and
Filled ‘er up and everything seems fine.
Is the increased capacity fact or fiction or
Is there another reason for this somewhat hillbilly arrangement?
Al
There should be a large spring and a flat washer in front of the oil filter. This pushes the filter almost off the oil filter bolt as you go to screw the bolt into the boss on the front of the engine. Then the spring holds the filter right up against that boss when you snug down the filter housing.
An aside of advice: if you attempt to use the large O-ring that comes along with oil filters nowadays, it WILL leak oil from a warmed-up engine, dripping off the bottom of the filter housing. The proper O-ring is made for Honda and is so thick that you almost suspect it is too thick: that's the correct one. If the one you have just lays in the groove, even having some slack, it is the one used by Kawasaki and Suzuki (they used the same oil filter housing after 1978) and it should be replaced. Many of these oil filter housings get broken from folks tightening them too tight because of this issue: they just need to be snugged down, with the proper O-ring.
The difference is due to the type of oiling systems used in the other bikes: they are much lower flow and pressure than is found in yours. They all used the same housing because after the 750 was discontinued the vendor owned the rights to these parts.
