If it wasn't done to get it running, new points, condensor, rotor and plugs should be installed. depending upon their condition, replace the dist cap and plug wires too. Basically a good general tuneup.
Timing could cause your symptoms. The points could have closed up or perhaps the dist wasn't tightened up enough and has moved. Wires could be loose in the dist and/or on the coil. So double check timing and all connections.
Besides the tuneup a fuel delivery problem can also cause your symptoms.
Crud getting into the carb can cause the float not to close and flood the engine (in this case you should have seen black smoke). The main jet could be partially clogged as well as any of the internal passages. Make sure the choke is fully open when it's supposed to be.
The Carb may need disassembled and cleaned out/rebuilt. Basic kits run less than $20.
Another check would be to cup your hand over the carb while idleing to see if the idle picks up. If it does you have a vacuum leak, perhaps where the carb bolts to the insulator on the manifold. Make sure the nuts are tight. If the idle doesn't pickup or it stalls the engine it probably isn't a vacuum leak.
I wouldn't suspect anything serious until all the basic easy fixes have been done.
These 216's run great when setup correctly.
Course it could be just a problem w/the plug(s).
Good luck
Dave
