I was digging around in the Haynes manual and I came across something weird regarding the crancase ventilation (bottom of pg 71 in the 140 manual if anyone cares). I have a B20 engine (it is stamped B20 on the side), but it looks like the B18 picture, air filters and all.
Specifically, according to the book on a B20 engine,
-The hose from the crankcase breather connects to the big box air cleaner.
-The hose from the oil filler cap connects to the manifold.
Well, mine is connected backwards.
-The hose from the crankcase breather goes to my manifold.
-The hose from the oil filler goes to my round air cleaner.
On my 2 SU carbs I do have individual round air filters (like the picture of the B18) unlike the big box that fits over the pair. Is this type of air filter something that came standard or most likely aftermarket? Could it be carbs from a B18 that have been put on the engine?

Since I don't really know about this, would it cause any harm to switch the hoses and see how it runs? It seems it is all just air flow to/from the case, wouldn't it run fine without any hoses, much less swapped ones?

Thanks,
Phil