I had the opportunity to read through the service manual the other day and I found something interesting. I need to figure the oiling system out.

The manual says to set the oil pump to 28 drops per minute at Idle. You can set this by putting a “test plug” in the oil pump and count the drips coming out of it.

I am going to make one of these test plugs . Here is the kicker. I was told by a rider over here to use later model pistons in the 101’s with an oil ring. So I did my bikes. No problems yet.

According to the book, the 101’s should use 1 quart of oil per 100 miles. (This seems excessive to me) this is with a two ring piston. Well, if we set our oil pumps to 28 drops and we don’t use oil through the rings, We are going to end up with too much oil in the crank case.  I want to find balance. I do not want to burn 1 quart of oil per 100.

Any advise?

My 101 does not have an oil ring and behaves as described except oil use is closer to 200 miles/qt than 100.  I find that I need to check oil level frequently, and fiddle with the metering "pump".  I added a petcock to make it easier.  With the 2-ring pistons, a little excess oil gets burned, which is OK, & way too much will cause smoking.

I learned more about oiling old motors with the 1916 Henderson inline 4 cyl single-speed that I tuned and rode in this year's Cannonball Run.  The engine has babbit bearings and a shallow sump with splash lubrication from little projections on the rods.  It has a dry external clutch. The OEM setup used enough oil that there was a drip arrangement, without a pump.  The modern build uses an oil ring and does away with the drip system, running the engine line a lawn mower.  The empty oil tank is used for reserve gasoline.  The engine consistently used 1oz of oil/12 miles when driven on a local course where the average speed is 45-50 mph.

During the run, the oil was changed every day, using Red Line full synthetic motorcycle oil (designed specifically for modern Harleys).  1 quart would overfill by 5 oz.  I added oil at lunch stops, where it would be down several oz.  Level checking was via petcock as on a 101.  I changed the petcock to a "full flow" ball valve with a large passage to make the process easier.