B33-2 250cc ohv felt washers

[Crumblingcliff]

Should there be a felt washer (29-811) between the crankcase and the primary drive sprocket?
My bike seems to be allowing a lot of oil out of the shaft here, all chains well lubricated, but it is also covering the rear wheel.
Reading I believe that there should be some oil from here to lubricate the primary chain.

[Steve.S]

Yes there should. It fits in a deep "groove or well" (I don't know what to call it), in the crankcase, and would normally be fitted before the crankshaft is fitted.
However, I have managed to poke one in there with the engine assembled, using a screwdriver. I also put a few dabs of silicone sealant in the well, to try to stop the felt from turning with the crankshaft. If it's missing, I'm not surprised oil is coming out.
Hope this helps.
Steve.

[militaryron]

In case you ever need to strip the engine? I've replaced the outer drive side main bearing on my WB30 engine with a sealed bearing but removed the inner seal. The same thing with the main gearbox bearing. I do it to all gearbox builds now. Doesn't have reduce the oil leaks. Ron

[Crumblingcliff]

Steve, Ron,
Thanks for confirming my suspicion that the felt washer was missing.
Any ideas on what size is required, the one listed in the spares catalogue does not seem to be available.
Many thanks and regards
Simon

[Steve.S]

If your model is 1933, it will not have a cush drive.
If you remove the crankshaft nut, maglita sprocket, spacer, and engine sprocket, then, behind the engine sprocket is another spacer on which the felt seal runs. I think you will find the OD of this spacer is 1 1/4". So I fitted a felt seal:
1 5/8" OD (approx)
1 1/4" ID
3/8" thick, or perhaps just a bit over.
I think with the spacer removed, you should be able to squeeze a felt washer in there.
BTW, have you had any problems with your Maglita drive chain? I found fitting a wider chain solved my problems.
Steve.

[Crumblingcliff]

Steve,
Thanks for the information, I do not have spacer on the inside of the primary sprocket, but I do have a felt washer in the casing.
Looks like I am making a spacer for the felt washer to run on.
The primary sprocket is new, old one machined off and a new one badly welded on,  going to run with this as I cannot go to a new custom sprocket at this moment, already had 2 made.
Maglita chain is ok. The bike runs much better now it has a lot of the slack taken out of it.
Thanks
Simon

[Crumblingcliff]

Steve,
Update on this. No 1.25in material so made a inch dia spacer and have fitted a 25 id x 32 od seal and glued this in place.
The felt washer I could see was one made to fill the void where the spacer should have been, the 1.25 id x 1.625 od felt washer was there but was very tired and probably would not have worked anyway.
Waiting for the seal adhesive to go off before I try it.
One question, does the crankcase breathe through the shaft with the sprockets on?
Thanks
Simon

[Steve.S]

Simon, Yes, the mainshaft has a hole right the way through it, and the engine breathes through this.
It also breathes through the pipe screwed into the crankcase wall. This is meant to lubricate the chains. 
I am rather puzzled about your missing spacer. In addition to providing a surface for the felt seal to run on, it also allows the mainshaft to be fully tightend against the main bearing, so when assembled, crankshaft endfloat is nil. I assume that the mainshaft nut must have been tightened until the sprocket was at the end of the mainshaft  splines, so not pulling the mainshaft up against the bearing. Depending on clearances, this could mean that the crankshaft was moving about all over the place. Quite alarming.
You must use a straight edge against the engine and clutch sprockets to make sure they are in line, and so determine the thickness of the spacer.
You may also need to move the Maglita across to line those sprockets up.
Finally, (something to bear in mind for the future), there are 2 clutch hubs available. One has a boss on the inner face, and the other is flush. This makes a difference to sprocket alignment.
Steve.

[Crumblingcliff]

Steve,
Spacer and seal all in place, no oil leaking out round the crankshaft.
I had measured everything up to get all the sprockets lined up.
Thought it was odd that the sprocket was just tightened up to the end of the splines.
The bike is a bitsa so I am not surprised that I keep finding things that are not as they should be.
Thanks for the information.
Regards
Simon

[Crumblingcliff]

Went for a 20 mile ride today, still oil leaking but not as much as previously. Guess that's another fix.
Regards
Simon

[Steve.S]

Simon,
Don't forget the B2 has a total loss oiling system. If oil does not drip after a run, there is something wrong. I would expect one or two teaspoons of oil under the engine after leaving the motorcycle for about an hour. If it's a lot more than that, you might want to check how many drops of oil your Pilgrim pump is set at. BSA recommended 14 to 16 drops per minute, I assume at normal running speed. I set mine to 1 drop every 4 seconds at tickover speed.
However, I think the most important thing is to ensure there is a hint of blue smoke from the exhaust when opening the throttle after going down a short hill with the throttle closed (assuming the piston rings are in good order). This indicates to me that engine lubrication is about right.
If you still have a problem BSA Service Sheet No.48 (in the Club Library) mentions a restrictor bush fitted to the chain oiler stud, although you don't have a trough in your chaincase. The Bruce Main Smith green book of BSA's 1935 to 1940 also mentions this as having an ID of 0.46".