Have been noticing for a while that theres not much power when you mash it from a stand, it just gradually gains, no bogs or anything weird though. So decide to mess with the timing and came to conclusion that it was good, but while playing around noticed theres a vacuum sound coming from the valve cover/oil fill. Bad valve seat? Maybe its burnt up? Not crazy loud or anything, just notice when you turn her off, you hear it for a second or two after everything has stopped.