Originally Posted by JayC
50:1 is not enough oil, IMHO, especially for a bitty engine like a chainsaw that runs WFO all the time. I generally run roughly 25:1 in my saws, and never less than 32:1 (32:1 only when using a high-performance oil like Yamalube).
JayC
If you don't choke your engine with clogged air filters, and keep your carb adjusted to the enviroment spark plug fouling isn't a problem. I run 15 to 1 to 28 to 1 from the late seventies until now for the most part. I don't remember fouling a plug of my own since my first motorcycle in 1973. I didn't know enough to clean the air filter and did the break in in the manual, (not exceeding 4000 rpms. etc.). In fact I know an old farm boy that cut more then a little wood with an Echo 660 since the mid 1980's and about 2 years ago we were looking at his saw and it still had the original spark plug with orange echo paint. His dad an airplane mechanic + taught him to mix 1 quart of motor oil to a 5 gallon can of gas ( 20 to 1 ) and shake it up before each use and my friend said he always to this day mixes his that way with shell rotella and never has had a problem. About 2 to 3 years after his Dad died we drug his JD 70v out from under the work bench and I insisted he change gas before trying to start it after that amount of time it but he just shook it up in the saw a bit and it fired in little more then a few pulls and run fine.
I am not saying everybody should do likewise because the benefits each individual is looking for aren't the same. If your running a new saw and expect the warranty to be valid, follow the rules, can't keep your saw tuned at 25 to 1 ( I can ) better use something else. Not so good quality oils leave more carbon then good oil with fresh gas and sometimes significant enouh to cause a problem. Not so good oil likely could not be enough lubrication at 50 to 1 in extreme conditions and likely could ruin your engine way faster then some carbon build up would. People want to blame oil for this and that and so have I, but its usually something else they neglected by far the biggest problem.
If find a good synthetic at a good price I might switch to 40 to 1. I like the idea of less smoke and carbon even though I haven't been having enough to be a problem with either in my personal equipment. I buy,sell and trade several chainsaws a year and I've gotten many that were fairly loaded with carbon and most often a clogged air filter to boot. Probably how they were kept most their life. I went from 24 to 1 to 28 to 1 (5oz to a gallon of premium) about a year ago, I did wreck an 044 engine using some very old Stihl oil but I am not sure the cause as I did some amature work to the ports prior. I quit using the old oil and went back to what I usually buy, I think its Champion 2 cycle for air cooled that I have been using most for the last 10 or more years with no problems. 50 to 1 synthetic goes in my 4 mix and I'd probably use it if I bought a saw under warranty. I could use it for every thing but I lean towards extra lubrication with out any problems, especially in engines with high hours.