Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hello and thank you for using JustAnswer.The main reason behind this is Stihl's ratio is assuming you are using a premium gas and premium 2 cycle oil (THEIR OIL). If you use a cheap 2 cycle oil the ratio would be more in line with 25:1 or 30:1 even for Stihl. The chinese just want to make sure there (junk) is well protected. Also the steel and internals are a lot of times not the same quality so they do not want to take a chance at running that at 50:1...could make for a seized engine. So they are just being safe with the ratio's. If you run a better grade oil you could thin the ratio out on the chines one, but why do that if it runs good leave it be.
I was wondering if the chinese did not bother to coat the bore of their machines as do Stihl and Huskvana and thus need more oil to lessen wear or pick up. Bearings may also be of poor quality, as you say, and need more oil.