If the oil tank is gone and the oil pump is removed and the cover sealed off you MUST premix gas/oil at 40:1 ratio. Yes, this lubricates all the innards of the engine ... except:
The other issue is how oil is fed to the rotary valve gears which live between the cylinders. There is an oil feed into the crankcase under the carb which originally was fed by a connection under the oil tank and a return oil line from the crankcase over the carb which originally connected to a connection at the top of the oil tank. You MUST have oil in these lines else risk munching the rotary valve gears which means a major teardown and, if luck is not with you, a possible lunched crankshaft. Some have added an external reservoir to feed these lines or just connect a line between the input and return lines on the crankcase; in either case you need to use clear lines so you can see and insure oil level to the rotary gears is adequate.
I am in the camp that says to keep the original oil injection system, it is very reliable. You can test the oil pump with a drill (and possibly 3 hands). The "banjo" fittings on the oil pump to which the small oil lines to the intake are connected have a check ball in them that you can test (after cleaning out with solvent) with mouth pressure and a length of the small oil line. Because the oil flow from the oil pump is metered depending on throttle setting your oil consumption will be less than when using pre-mix where the fuel/oil mix is the same no matter what speed.
Have fun with the old Doo and enjoy the forum, best in the world. Fire away with questions, you will get an answer.
Rod
