The backing plate that the air filter attaches to has a threaded through-and-through hole that has a nozzle fitting you screw into the back of that hole that accepts a hose. That hose is supposed to go "to the crankcase". If I'm understanding you correctly, I should plug that fitting? BTW, I did find a crude schematic in the factory guide like you suggested. It shows the oil pump with a tube traveling up to the air cleaner called "crankcase vent". What and where that "tube" is and how to join or get it into the crankcase and what hole in the crankcase-is still a mystery to me. I prefer your rec to ignore or plug.

 

In your case plug all holes in the air cleaner back plate to make sure all the air going into your engine is going through your air filter.

 

Yeah, plug the hole. The hose from the crank case should point down (and not be plugged, of course).

 

If you connect the hose to the air breather, at some point you will have at least a 1/2 quart of oil on your leg when the engine wet sumps...it will happen. The hose connection to run to the ground is in red.

 

Thanks to your help (that picture), I found the breather. It projects rearward on the horizontal and is just an open hole. Unfortunately there is only about 1/16th inch of threads protruding from it, so there is not an easy way to attach the breather hose to it.

So having found that it is venting at the case, and not finding an easy way to connect the air filter to it, is it your opinion that I should block all holes coming out of the S & S back plate including the metal breather elbow screwed into the carb back plate?