Swedishbiker, you mention changing out the engine, so you opened the door for this little factiod nugget.
I used to razz Routy about the vac petcock being a potential cause for early onset oil consumption. He loved to razz me back.
He got to razz me back because there was no evidence at that time that leaning out the engine repeatedly at speed when the vac petcock was failing did anything bad to the engine itself.
So I started keeping up with it -- we are up to 3 incidents where it the vac petcock has started to go bad and then the newbie got some power loss. Two of them wound up tearing the engine down and found ring zone scuffing damage (collapsed ring grooves & seized rings) were present.
Guess what they call a milder form of this sort of piston / ring groove damage?

Yep, early onset oil consumption ....

Now we are asking the newbies who come on the list with questions about sudden onset heavy oil consumption if they are running the stock vac petcock.
So far all of them are.
Yes, I know -- not proof. Chicken or egg came first .... it is debatable from either side. Still, vac petcock leads to lean out stalling which has secondary effects on various things like all lean running conditions do.
But one thing we do know FACTUALLY, the folks who have taken off the vac petcock have NOT had to suffer through any of the half dozen petcock related heartaches we used to have to coax them through.
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Plus there is that little trick about the failing vacsucker petcock that can result in a real gasoline dripping fire hazard.