Oil change - filter differences.

[furious_blue_imp]

Honda's reputation for reliability was built in large part on those centrifugal oil filters. From the first step-through 50s, through the DOHC 450s, and still today as Tev62 says. I remember servicing tons of them, pulling off the filter or clutch covers, scraping out packed-in metallic sludge, sometimes 1/2" thick. They are remarkably effective but become less so as they fill up.

I've been under the impression that fine oil filtration is not necessary if the engine has non-plain bearing crankshaft journals (?). With ball or roller bearings handling the heavy loads there is not the dependence on having a fine high pressure layer of oil between surfaces to discourage metal-on-metal contact as with plain bearings. True ?
My old CB350 was like that and my XS650 is like that. The XS650 OHC runs on ball bearings, I can't remember what kind of cam bearings are on the CB350.

I've been under the impression that fine oil filtration is not necessary if the engine has non-plain bearing crankshaft journals (?). With ball or roller bearings handling the heavy loads there is not the dependence on having a fine high pressure layer of oil between surfaces to discourage metal-on-metal contact as with plain bearings. True ?
My old CB350 was like that and my XS650 is like that. The XS650 OHC runs on ball bearings, I can't remember what kind of cam bearings are on the CB350. Yes, true. The centrifugal oil filters are used only on Hondas with ball and roller bearing bearing cranks, up to the '76 CB500T. They never used them on plain-bearing cranks. Like all plain-bearing cranks, old British bikes had sludge traps in their crankshafts. Without an actual paper filter, their cranks needed to be taken out, the grub screws un-pinned and removed, cleaned out and re-staked as part of their long term maintenance schedule.

OMG, what a pain. I'm glad I started on the newer Japanese bikes of the early '70s. I remember reading maintenance manuals on British bikes that described how one was supposed to set up a dial indicator on top of the piston so that you can detect Top Dead Center properly so that you could attach the degree wheel accurately so that you could move the crankshaft to the proper position in order to set the valves and the ignition timing. I guess I missed all that and was spoiled by the simpler Japanese bike method of lining up prescribed marks that were already permanently in place, I had it pretty easy by comparison.
That and the Japanese introducing the new concept that all you had to do with a motorcycle was to ride it, instead of spending endless unpredictable hours tinkering to keep it going, no wonder they took over the market..

[Cormanus]

Ha! I also fell into the Japanese trap. When I started out on my little Honda, I spent a lot of time riding to visit various mates whose British bikes were in bits all over their garage floor. One of the downsides was that I never learned much about mechanical work.