I have a HRX217HXA with BBC that I use for my smaller accounts and it's been running a little slow. I tached it yesterday at only 3100 with the blade engaged. I maxed out the throttle cable so it's to the point of almost getting the choke to engage so it's not a cable issue. The rpms are also within 50 regardless if the blade is engaged or not so the governor is doing it's job. I heard there's a screw on the carb that I can use to adjust the top speed. Where do I find it? Thanks! I would like to take it to a "safe" rpm of at least 3300-3400.