The oil consumption is so individual so it is hard to tell a span how far you can ride on the amount in the crankcase until damage occurs. Death wall riders are reporting 5-7 minute shows with no oil pump mounted, just regular checks and fillups when needed.

Frequent level checks at the level plug on the left hand side crankcase is the only way. To me, normal level is when some oil flow out when I remove the plug. I decrease the pump delivery when 2/3dl (75ml) escapes and increase if no oil is escaping. 1/4 turns on the screw, never more than 1/2 turn at a time.

The Indian factory had a special tool made that could be ordered from your nearest Indian dealer, a oiler test plug screwed in instead of the bottom plug in the pump. This test plug shuts off the flow to the cam case and allows it to drip out of the test plug, showing just how much oil is being pumped. Plug and test described in the R&O. 

But to check if the oiler turns is a bit, if not difficult but slobby. Disconnect the oil line from the oiler and remove the fillister drain screw just below the oil tube coupling. Visible check in the screw hole if the pump drum inside the pump body is turning. Don't probe in the hole with anything, the drum can catch that and destroy the pump! 

The drum is turning very slowly, it takes 19 revolutions of the crankshaft  to turn the drum one revolution! With one turn of the drum, it delivers 2 squirts of oil. The squirts are very lazy at kicking speed, oil just dripping out. 

This checkup is not complete, it  does not show if the pistons inside the drum is stuck, springs broken or if the slanted washer inside is rusted solid (very dangerous), so best is to disassemble the pump entirely.

I only have 1928-30 pumps at hand, so can't tell how to diagnosticly check 1931 pumps. A diagnostic checkup on the 1928-30 pump can be done with removing the adjusting screw and inserting a metal rod in the hole, pushing to feel if the slanted washer and pistons is moving and springing back smoothly. It should be able to push in some 9mm's with not much effort. However it is not possible to feel if one of the 2 pistons are stuck. I removed one of the pistons to feel if the washer is undulating when the drum is turning (cam turned with a drill), but could not get an affirmative feel of that happening.

If all is ok, a squirt of oil or grease in the compartment through the screw hole is not bad on a pump that hasn't been in use for a long time. Condensed water can make rust in that front end of the pump compartment.

Base adjustment of the screw is very dangerous to say as it depends on the state of the engine. An original screw has a rounded top and 19mm long shank. The head is 3,2mm thick, so in total about 22,2mm long. The original stopnut is also 3,2mm thick. When the nut is tight to the head and the screw is fully in, the pump does not deliver any oil. The book says with the testplug, 28 maybe down to to 18 drops per minute on a new engine. Dont hold me accountable, but on a 1928-30 pump, 4 full turns out on the screw is a start...

Danny, if you add no oil, you may have about 15-20 miles before disaster.

I use an shut off tap in the level plug to make it easier to check, and when running a bike in, I check the level regularly.( Learnt this tip off ALex Fergueson in the Albury Wodonga  area when I first started playing with 101s, he had plenty of experience, its a good idea, as its amazing how lazy you can get because lying on the floor wiith a long screwdriver is a pain in the rear, leaniing down from the saddle and opening a shut off is a lot easier.)  I basically do a head bolt nip at 1 minute, 1 mile, 5 miles, then 20 mile intervals until they stop moving( usually around 80 miles for the composite head gaskets, and thats at around 35 ft/lbs. As  I am stopped I then check the oil level, have a smoke and drain level into a coffee cup. I am generally quite boring about this, and have routes planned with nice viewing points/cafes for known mileages, and I get to know the hills that I can judge performance on. 

Also bear in mind that if you remove the oil line you need to bleed any air out of the line by using the small bleed screw. Tapping the line gently with a screwdriver handle , you will be surprised how many bubbles come out for a while. It may clear, and may not airlock, but why take the risk?

 Having set the oil pump up to give the approx 28 drops at around 30-35 mph cruising speed( I use a little lathe and an old broken timing cover, but find that this generally coincides pretty closely with the test plug with a hole in it on the bike) , I am usually over oiling, and keep it that way until I really know what is happening. I extend smoke breaks but for the first few hundred miles will be checking oil level at least every 50 miles, judging how much I drain off. When I am happy that I am over oiling ( not too much build up as I am draining excess at the stops), I adjust the pump no more than a 1/4 of a turn at a time. 

Obviously this whole process is difficult to judge if you are using the hand pump to add oil between checks.

The actual amount I aim for is around 1/4 of an inch in the coffee cup, at around 40-45 mph after 50 miles) This will be more at 30-35, but as you run the motor in and increase speeds, you will find that what is way too much at 35 will be about right at 50, but goes exponential if you have a short blast at 60-65, you will nip the motor in no time.( have nearly done it twice trying to keep up with a Vincent and racing a friend on a Harley 45. If you feels a fluffiness in the motor, and a slight loss of power, pull in the clutch and coast to a halt. You will do no harm, but are seconds away from an expensive hand grenade.).Thats where the hand oil pump comes in. 

A little puff of smoke on the overrun is fine, constant smoke from overoiling is not good, too much oil will badly overheat the engine from friction drag, and you will clag up your piston and valves /head with carbon build up. 

 Eventually you will work out the oiling to suit your general riding, on a stock run in  101 I am happy to sit at around 55mph near enough all day, the motor is humming then. others may ride slower , some may ride a little faster, and hilly terrain will entail periods of higher revs. 

I also find that oil consumption will drop off markedly when the rings have bedded in, this is usually well on the way and noticeable at around 600-800 miles on  a fresh motor. Jorgen Sundberg in Sweden recommends a 1500 mile running in period before heavy throttle use.