Hi Colliin, here are four links which youíll find helpful I suspect. If youíre getting oil in the air cleaner assembly you probably have problems with the PCV system. Get a new PCV valve, about $4 or so and check the hose from the valve to the back of the carb at the base. Make sure itís clear and that the inlet on the carb is clear as well. There originally was a solenoid valve in the PCV line physically located between the carb and the head which was designed to block gases from flowing at idle; this was recalled later and removed. If you still have it then run a hose straight from the PCV valve to the carb connection. You can leave the solenoid connected to itís electrical plug and just tuck it away somewhere because itís neutralized, or unplug it and put it in your box of stuff.
Read the topics in the center column of the third link regarding setting the carb idle. The factory settings for the mixture screws is 2.5 turns out from a gently seated bottom. Both screws are set equally, so thatís a good starting point. If you want to tune it then the Best Lean Idle method is a good way to go. Connect a vac gauge to manvac. (If you still have all the emissions equipment, disconnect the larger manifold vac line from the vac reservoir under the battery and plug the gauge in that; this will also neutralize the Pulse Air and Solvac systems while youíre tuning which is a good idea.) With the engine at operating temp and idling, turn both mixture screws in 1/8 turn, bump the throttle a little and wait 15 seconds before doing it again; continue until you reach maximum vac reading and then back each one out 1/8 turn and youíre done.
If you want to verify your tune, put a multi-meter in line between the O2 sensor and itís connection. You should have about .6 volts (+/- .05v) at idle; .1v is lean and .9v is rich.
Hereís the links:
How to read a vacuum gauge:
How to read spark plugs:
Whatís under the hood:
Carter BBD Factory Service Manual:
If you wish to rebuild the carb itís easy and the rebuild kit is only about $20, BBD model 8384. Just make sure that you soak it generously with spray carb cleaner (get one with a spray tube on the can to blast it into the channels), let it soak for a 30 minutes or so, blow all of the channels out thoroughly, and then repeat the procedure. Make sure the venturi tubes are clear and that all of the tiny holes in the venturi cluster are clear (use a fine brass or copper wire if necessary.) During reassembly lightly grease (axle grease) the cup that the accelerator pump seats in and make sure that the larger ball bearing goes in the cup. The smaller ball bearing is in the venturi cluster.
As to vacuum readings for manvac, a healthy engine with no vac leaks should be around 22" HG at sea level. Subtract 1" HG for every increase in altitude of 1000 feet. Iím at 9000 and read 15" HG.
I hope this helps. Let us know how it goes.