I was told by the dealer where I bought my 4 mix stuff that the one-time valve adjustment was not longer necessary. I thought it was strange so I questioned them about it, but they assured me it was not needed, and that because it was a maintenance item it was not covered by warranty anyway. They said they would look at it if it was running funny, but it's running fine, I just wanted to get the valves adjusted like it says in the manual. Is this right? Was there a service bulletin that says a one time valve adjustment is not needed anymore, as they claimed at the dealer?