Also meant to keep air in. If air is blowing out of the seal the mixture will be rich and you end up leaning your saw out to compensate. But like I say I'm with greasy shop rag any leaks at all I'm not ok with it. That nightmare 441 was and extremely slow leak which is why it took me months to find.... plus who would ever expect and invisible micro crack to cause a saw not to run right. I know husqvarna has a rule in their shop manuals that it can leak down x amount in 5 minutes and it's considered good, I just don't like any kind of air leak so if it don't hold full 7.5lbs of pressure and 7.4 mercury for at least 5 mins chainsawredeemer85 is havin a talk with that saw 😆
