Question About Kohler Breathers

[stihl here]

I own two Kohlers, a horizontal shaft CH740 and a vertical shaft ECV740. The CH740 has a reed to control crankcase pressure under the center cover at the oil pressure switch. The ECV740 has the center cover but the parts diagram shows no reed nor is there a hose going to that cover. Instead, it has a catch can in one valve cover with a hose going to the intake manifold. I can blow through that catch can from either direction, so is this normal or is there a defective one-way valve inside it? Doesn't make sense to control the crankcase pressure on one engine and not the other but the ECV740 has a pulse operated fuel pump the seems to work so I'm not sure what's going on, if anything. Appreciate the help.

 

[EFSM]

Is the hose going to to the intake manifold between the throttle body and the heads? If so, that is a low-pressure area and will be drawing a vacuum. The reason that can't be done on your CH740 is that is is carbureted, and it would be impossible for the carburetor to adjust for more or less blow-by as the engine breaks in and wears.