Hi Chirs.
Oil, straight non detergent classic oil ideal, but realistically Morris 20/50 etc for old vehicles at a pinch. Below 60F Indian specified a straight 30, the difference in drag on the engine is noticeable at the wrist, but a 30 weight will find its way out of every orifice a lot easier. I like an sae 40, but use 50 on customers bikes because thats what they want, and you can get all fighty about oils.
Oil not separated between engine and clutch except by a cork washer behind the drive gear, altho in practice, very little will actually move from the engine to the primary unless you have breathing issues, see catch can answer.
Oil level, when filling up to drain plug below the clutch arm, give it a few minutes rest, it may take a couple of minutes in cold weather to flow fully into gearbox.
The primer cups are really only there for cold weather when running on 1930s oils, the castor oil stuff goes like glue . As an aside, I have seen a lovely pic of a 50 gallon drum of oil sitting on a gas burner at Brooklands in the twenties, preheating the oil on a cold day before adding to bikes, for that reason. If they don't leak, don't mess with them. Decoration only, I usually fill cups up with a dab of grease to check that they are not blowing. Similarly, if doing a decoke, leave the carbon build up in the holes to aid block up. A lot of guys will fit a screw in there instead of replacing damaged primer cup.
The bikes had a decompression cam in the timing chest that acts on the arms attached to the exhaust cam followers, lifting the valves as a kill switch. If yours doesn't have this, fitted ( either not available when built, or 741 cam followers used, for example), there is an earth point on the mag that you can fit a horn button to as a kill switch. Failing that, flick the carb to full choke and retard the spark, should do the job.
Catch can :- only needed if engine over oiling and pressurizing crankcase. The early 28 bikes with a breather on the left side will blow out oil whatever you do, and if they don't have the breather disc inside the cam case between timing chest and motor, it will be worse. There was an update in July 1929 that moves the breather to the cam case opposite the timing gear, and removing the internal breather. Can try and post a pic of service shot if thats what you need. If its a stroker, you may need the catch can anyway.
Oil level needs keeping tabs on, as John says, until you get used to the way you ride and the levels. If you run with way too much oil in the crankcase, the drag will be unbeleivable, and the motor will overheat .
This forum reminds me how blessed we are, sensible answers from people that ride the bikes, and no politics, offers of good local hot chicks, or recommendations for wonder herbal remedies.
Hope some of this helps.
NEXT ???
PS, Any idea what happened to Robin Oakley? Last time I called his daughter put the phone down on me for some reason. Miss his chats over cups of tea and roll ups. I know he was diagnosed with vascular dementia, and needed his lines cleaned, was hoping maybe that would have helped.
