Could someone please tell me how to adjust the maxium engine RPM's on a 16 HP B&S Vanguard V-Twin. The engine is on a 52inch Wright Stander and is only running at 3500 RPM's. I would like to up to at least 3600 RPM's like the owners manual says to run it at. But the B&S owners manual only shows how to adjust the low idle RPM's. Anyone with any info please help.