When I bought my 131 a few years ago, there was all kinds of rumors on the 4 mix engine and it's flaws. Not had any trouble with mine. easy starting and will go a long way on a tank of fuel. It sounds funny compared to a 2 stroke saw. it has plenty of torque and I men plenty. it came with a 12 inch bar but I run a 14 on it. I have run mine fully extended most of the times and a two hour run with it fully extended will wear you out. I even use it to cut smaller springpoles so I don't have to be close. have cut limbs up to 16 inches with it before. Always make a cut underneath the limb before you top cut it so it won't pinch the bar and stick.