As far as I can gather, the outer of the 2 washers 24-4225 will be locked up against the inner race of the bearing when the sprocket ring nut is tightened, and will rotate with the sprocket.
However,since it is dished (or rebated by 0.003") the outer diameter of the washer will be pressed against the stationary outer bearing race.
Although this will give rudimentary sealing,it seems to me that it will also wear the washer, and iron filings will get into the bearing.
Or is the theory that since there will be oil in the bearing, this will prevent wear?
Maybe my pattern washer has too large an OD, and it should just fit snugly inside the inner race without touching it?
Any ideas?

Steve the general consensus these days is to fit a sealed bearing and not have to worry any more about oil leaks through the bearing. Opinion is divided about whether to remove the inner seal or not.....Personally, I remove it. Ron

email (option): ronpier@talk21.com

Sorry. Got confused. I meant to write "inside the outer race".

I have run sealed bearings on the output bearing on B50's for over 20 years now. The seals will still allow oil to pass into them at a very reduced rate. You could run shielded bearings that pass more oil, but still help keep debris out. Keeping debris out of their raceways seriously improves their life. Also remember ball and roller bearings don't like being flooded with oil or they will overheat pushing it out.

email (option): pes.sales@btconnect.com

If ball and roller bearings don't like being flooded with oil, how do they manage inside engines. The outer bearing on an M20 or a B31/b33 are all soaking in oil and on the BSA twins they have an oil seal to keep the oil inside the engine.

Over heating problems in bearings generally apply to grease lubricated bearings (unless an oil lubricated bearing has insufficient supply)...When the bearing is over packed with grease this increases friction resulting in increased temperatures and possible premature failure...The 'fill quantity' of bearings should be correct, in other words the amount of available space within the bearing should not be overfilled...30% of the available space filled with grease is a general guide...Quite how that is calculated for an open bearing in the home workshop is another matter...

Oil lubricated open bearings, whether drip fed, splash fed, force fed or flooded don't suffer from that particular problem...In fact the oil in a flooded bearing application is generally intended to cool the bearing as well as to lubricate it...In the M20 gearbox for example, the main bearing is 'flooded' as its lower edge sits more or less level with the 'floor' of the gearbox which contains a pint of oil...That is why I remove the inner seal when using a sealed bearing, to maintain this condition..The big end is a good example of a 'force fed' bearing and the main bearings a splash fed application....Ian

email (option): ian@wright52.plus.com

Thanks for that, Ron. I have, in fact fitted a sealed bearing, and it doesn't leak on the bench. Interestingly, there seem to be 2 types of rubber sealed bearings... Contact and Non Contact.
With LLB type bearing, the seal does not contact the inner race, but with the LLU bearing, it does.

Unfortunately, I've become interested in how the original design worked. (sort of).

I've checked the size of my washer, and it's exactly the same size as given in Neale Gentner's tips.
I don't know if you agree with my suggestion that the washer rubs on the bearing, but if so, I imagine it would be essential to omit the outer washer, otherwise the seal will be damaged by the filings? After all, it won't make any difference to mainshat endfloat.
(Later the same day...) I've just taken some measurements, and see that the washer OD is only 0.015" larger than the ID of the outer race (so, 0.0075" larger on diameter).
I've also looked at some old bearings and washers, and it seems that in use, the bearing only polishes the washer and doesn't grind it away.

Next question,can anyone confirm that the oil flinger washer 24-4235 at the kickstart end of the mainshaft, fits with the large diameter flinger part (and lip) against the mainshaft 1st gear?

Doesn't the distance washer #49 sit in the recess in the middle of the flinger? Ron

email (option): ronpier@talk21.com

Put too much oil through a roller big end and you will kill it for sure. This is the dilemma, as it's the waste oil from the big end that lubricates the bore in most engines. This is why my race engines have an improved lubrication system.

email (option): pes.sales@btconnect.com

Ron,
Thanks for the diagram.
There is no recess in my oil flinger washer. However, the outer diameter is curved over.
I think it fits with the curve towards the inside of the gearbox, next to mainshaft 1st gear. What do you reckon?

A picture would be useful...It shouldn't be 'curved over'....Ian

email (option): ian@wright52.plus.com

How important is that oil flinger? I heard that it's often missing! Ron

email (option): ronpier@talk21.com