These gas bangers were originaly designed for weed wackers so were made for the average dumb joe to use in his garden. I have at last count 8 Zenoahs and have never had any trouble. I used to go to the local motor cycle shop and buy their best racing oil then I discovered Lawn Boy ashless 2 stroke grass mower oil and have used it ever since. For the first few tank fulls I increase the oil mix by about 1/4. It works for me. BTW Lawn Boy oil is very cheap and Clean.