A vac petcock on a Savage has one noted strange quirk, at full running speed the vac level in the engine decreases slightly which partially decreases the fuel feed from the stock vac petcock. This can lead to a listed & known symptom of stock vac petcock malfunction (fuel starvation) which is exactly what he described in his first post.
He can do the test set up, make a high speed run, report the results and then get more "help" from there.
And you do know that vac lines can fail at any time, right? Verslagen replaces his vac line yearly as a matter of rote. If he tests "vac petcock system deficient" then I am sure someone will suggest replacing his vac line.
Key thing when a new person posts with a situation is to FIND OUT WHAT HIS SITUATION REALLY IS. The standard tests in Tech Section are designed to do this.
If anyone posts with a fuel related issue, to remove over half the of "unknown" from the situation use the http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429/1 test. Do it first thing, right off the bat, make the poster reply that he did the test and get him to tell us what he found out.
This will tell you instantly what he understands about the bike and what he doesn't understand. It also cuts out over half the fail modes instantly (no matter which half, half are GONE). Then you focus on what is left.