Originally Posted by
hondapop
There is definitely nowhere behind the manifold for oil to leak from, it will be coming from that cam-cover gasket, running down onto the manifold itself while the engine is standing, then creating smoke when you start up and it gets hot. The only thing you can do is use sealer, but, you'll need to wash every bit of old oil off it and the head surface for it to stick and reseal. I'm also guessing that the gasket has cracks and breaks in it. This is where it can get tricky. It's probably hardened and will break if you try to prise it out, but that may be your only recourse. You would then have to clean out the groove it fits into and the gasket itself of oil, then put sealer into the groove and press the gasket pieces back in, making sure the sealer gets between the broken ends. Then reapply the sealer to both faces before replacing the cover, gon'na be a bit messy.
I wouldn't try to get that sensor out without removing the engine or the radiator etc, because at this age and length of time it'll be stuck real tight. Haven't had any experience with the dual carb setups on these, but the dual choke single setups had an absolute plethora of small hoses (21 IIRC) and pipes attached for the anti-pollution system. PGM-FI is much simpler in that regard, although the type fitted back in the mid '80's had a lot also because they still used vacuum controls.