I am a little concerned with the power level of my 26 liquid cooled mower, with a 60" deck. The mower seems to bog down when cutting thick grass ( cutting between 3.5 and 4" hieght). The cut looks good other then the power level seeming to fall off. Mower has 5 hrs on it. This bothers me, for the main reason of my jd 757 with a 60" deck, 25 kaw. and 800 hours blows right through it. Is this normal? Should i take it to maybe have the rpms checked or suggestions on what to check? Thanks for your help.