Hey guys, I have an 09 TTHP 36"(Approx 250 Hrs) that is having some issues. When I fire it up it seems to be running like normal. However, when I engage the blades it has a loss in power to the point it runs slow and can't cut. This has happened in the past, but new plugs corrected the problem. New plugs did not do the trick this time. Please help. Thanks in advance.