I have a 1984 suzuki rm 125 it has always ran good for me. until recently it just putts and runs for maybe 20 secounds and then stalls. i tried to run start it and it kinda fired up but there was way more smoke then usually coming out of the exausht and it ran terribly. i changed the oil recently and had to use a 4 stroke oil cause i could not find 2 stroke anywhere could that be my problem or have i been mixing my fuel wrong?

Hello,,, i'm assuming this is a 2 cycle engine,,,, and it sounds like you used a much to thick oil mixture in your gas,,,,, if this is the case,,,,,, drain all gas from the tank,,,,, get 2 cycle oil,,,read the mixture info on the back label,,,,,be it 50/50,,,, 40/60,,,,, or whatever it all goes for on your specific bike,,,,, get a plastic baking mixing cup,,,and mark on there exactely how much oil to use for 1 gallon of fuel,,,,,,and go by that every time you need to make up a new mixture,,,,after you have done this,,,,and you now have the correct oil to gas mixture in your tank,,,install a new plug,,,,,or plugs,,,,, as i'm sure there pretty burnt out from the high oil content in gas you had,,,,,, and it should now run like new again,,,,correct oil to gas mixture on 2 cycles is extremely important ,,,, and when you rev it up,,you want to see a slight ,,white/blueish smoke out the exhaust,,,,,,but not to much,,,,, JOEL

Are you mixing regular motor oil in the fuel? Doesn't this bike have a reservoir for 2-stroke oil? You must use 2-stroke oil in that reservoir. Buy it online if you can't find it locally.