Our 97 was on high all the time as are all of our sister coaches. Different system obviously than yours as no extreme noises were noticed.
Changing the controller freed up 30-40 hp.
Bob,
What is the part number for the controller?
Split this out so as not to hijack the other OP's topic/request for assistance on a different era coach
Do not have it in front of me. Flite2010(bob) has the same dynamatic 199 degree controller.
Oregon coaches? Sells the unit if memory serves me.
Made in England commercial part. $700 range.
Maybe search my or bobs posts?