I just put one of these on my Lazer (25 hp Kohler), and have a couple of questions... 1. At full throttle with blades not engaged, the RPM is between 3400 to 3600. Just as I thought they are a little low, and I was planning to up them to 3750... But when I turned the blades on and began mowing they jump up to between 3900 and 4100 RPM..? WTF? Shouldn't they be around 3600? 2. Also why does the guage fluctuate between roughly a 200 RPM range, instead of staying on one number? When idling it only varies a few RPM right around 1750.