I'm betting some of you four strokers have been messing around with tachometers. I'm curious about what RPM would a person expect to be the Red Line RPM on a stock HS running unloaded?
This is exactly correct. They can only take it for short periods due to the lack of lubrication to the big end con rod. The con rod welds itself to the rod journal, often breaking or bending the con-rod in the process. You can modify the rod for a bit more oil flow, but this has to be done carefully. After that, I'm guessing the limiting factor would be the con-rod itself, oil slinger, or valve springs.Redline's about 8000, although they can take more than that for short bursts. The GXH50 can take it for a little longer than the HS can, due to tighter engine construction and a better connecting rod. Extended high RPM can cause the oil slinger to break off either engine, and even more extended may cause the connecting rod to break.
What you talking bout willis? If your power falls of then, you prolly got either a valve adjustment problem or something else going on...Same my power loss it around 5000 rpm