Been searching and can't seem to find any info on how the power valve works on these engines...specifically how the gear driven governor makes the valve close at upper RPMs.....I've heard different oil viscosities and temperatures can change the RPM the valve closes as well?

Also is there a general RPM setting the PV should close at??? I've heard 5800RPM on the 500's but nothing on the 250's.Obviously the pipe/engine combination will have some affect but just looking for a general starting point......Just trying to educate myself on the operating theory and gain some info.Thanks

Thanks Jerry..... ..Another question,does oil viscosity affect when the power valve closes??? For instance if you are using automatic transmission oil and set your PV to a certain RPM and then change to say a heavier 15w40 oil will the RPM the valve closes change drastically?
 6300 to 7000 rpm on the Lt250rs is range for LT250s.  The Power valve closing RPm point depends upon the porting and pipe combination.