Greetings. I haven't posted here as often as I used to in years past, but today I felt compelled. Now living atop a hill over a mile long with a very steep grade, the return trip home is often a useful diagnostic tool. The steep incline my 66cc HT can handle, albeit not terribly fast, without any assistance from my pedaling, IF ALL IS RIGHT. The Carb and throttle cable are tensioned properly and jetted ideally, fuel mixture is within ideal proportions, chains are greased and properly tensioned, and last but most important, TIRES ARE INFLATED to proper PSI. I cannot stress the last item enough. if either tire is even a tiny bit low, I'm peddling for certain at least on the steepest part of the hill. There are those frustrating times when something is off & I'm pedaling but I'll be damned if I can't figure out what the heck it is. Point being, keep your tires full (but not too full) makes for a better, safer ride and makes for a more powerful, consistently efficient engine. Low end, slow speed torque can make hill climbing with one of these difficult and properly inflated tires is one variable you have total control over. So use it!