Head gasket on these don't have fail in a way that causes engine running problems. The ones I have been all cause excessive oil usage. Matter of fact I just replaced last week. The engine did have another problem which was why I was replacing the cylinder in the first place. But when I was removing the head I found the head blown too. First one this year to replace. I replace 10 last year. A cylinder leak down test should tell if it is blown or not. And two years ago A new customer brought in a Hustler Super Z. The dealer shop told he needed a $4000 engine when in fact it was only a blown head gasket that cost $300 to replace. KInda funny that it would walk through 4 foot grass without bogging before I replaced the head gasket. And no smoke either.
PCV Reed valve is location inside the breather which is behind the flywheel. this the breather once the flywheel is removed.
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And this what is inside tThank you ill check it out.