Mike, I do mix 3 ounces of oil to one gallon of gas. I do run it as fast as it will go which is only about 25 mph. The sad thing is, is that when I bought it it did not have the airfilter or the silencer. How would I fix a siezed engine? or would I have to buy a new one? I hope I can fix it because I do not want to buy a new engine!!!