Here is the full link:
http://www.classicparker.com/phpBB3/viewtopic.php?f=19&t=10944
As you have guessed, burning that much oil is not normal. I've done a few 110+ mile trips and have had plenty of oil left in the reservoir.
I don't know much about the inner workings of the mechanical oil pump, but do know that it is solely controlled by the position of the throttle by way of a mechanical connection with the topmost throttle valve. The first thing you need to do is check out the oil control rod linkage and make sure it is still connected properly. Check that the white plastic clips on the ends of the control rod are not cracked or loose, etc.. When the throttle is closed, the oil pump lever should be resting right up against the stop.
Apparently these engines, when new are set to burn a little more oil during the initial burn in of the engine. At the first engine service, the oil control rod is supposed to be re-adjusted to normal oil burn rates, so if this service was never performed, you would be burning more oil.
If you really did burn a full tank of oil on 62 gallons of gas, then something else may be wrong, as this is way out of spec.
Take a look at the oil control rod and see if something is obviously wrong. I'd even recommend disconnecting the rod to take a good look at the plastic clip to make sure it isn't broken or cracked. Then re-assemble and make sure that the oil pump lever is resting against the stop pin when the throttle is in the idle position. (Technically, it is supposed to rest against the pin when the throttle valves are fully closed, which would require that you either disconnect the throttle link rod or back off the idle adjustment screw, but this is a small difference that you can ignore for now)
These aren't my pictures but they are a great reference.
The first pic shows the oil control rod, where it connects from the throttle valve on the first cylinder on the left and to the oil pump lever on the right. As the throttle is advanced, this rod moves the oil pump lever and causes more oil to be injected into the system.
The second pic shows a close-up of the oil pump lever. You can see the white plastic clip that attaches to the lever. You can pull the cotter pin, pop the clip off the control lever, loosen the nut and adjust the position of the clip by threading/unthreading it as necessary. Directly under the finger you can see where the oil pump lever rests against the stop pin.
What is interesting is that if the oil control rod was completely disconnected, the spring on the oil pump lever would basically cause the engine to inject less oil into the system.
So your control rod would have to be way out of whack to burn that much oil.
If the oil control rod is adjusted properly, there are only two other options that I can think of that could cause a problem.
The first would be if the system that determines when and how much oil gets pumped from the remote tank to the engine wasn't working properly and was overfilling the engine mounted tank. The overflow from the engine mounted tank would be injected back into the motor via a small hose that connects to the black intake silencer on the front of the engine. You could tell if this was happening by looking at the level of oil in the engine mounted tank. It should never reach the level of the cap and should remain about an inch below the top of the tank.
The only other thing I can think of is that there is a failure of the mechanical oil pump itself, which I don't know anything about as I haven't come across this issue before.
Let us know what you find out when you take a look at the oil control rod and level of oil in the engine mounted tank.
-- Tom
