gas and oil ratio

Discussion in '2-Stroke Engines' started by Ja22, Sep 20, 2010.

  1. Ja22

    Ja22 New Member

    hey how much oil do i put in a 80cc chinese motor with the gas tank they have provided? also what kind of oil do i use?

  2. unior

    unior Member

    Mix your fuel a gallon or 2 at a time in a seperate container. 32:1 once broken in. 20:1 ratio or something like that when new. I.E. 20 parts gas to 1 part oil. Use any 2 stroke premix oil.

    Also search as this topic has been covered thoroughly many times before.
  3. sheila

    sheila New Member

    I add 7oz. of 2 stroke oil to every one gallon of gas is this correct?
  4. AussieSteve

    AussieSteve Active Member

    I won't get into arguments about personal preferences, but with my 66cc HT the instructions recommended 16:1 during break-in, then 20:1 thereafter.

    sheila, 7oz per gallon equates to about 18:1. That's not bad. You could go a little lower on the oil if you want. 6.4oz per gallon is 20:1 or about 5oz per gallon for 25:1. There is no real need to go as low as 32:1. I run mine at 20:1 after about 1000km and my plug never fouls and is always a tan colour.
    Keep in mind that these engines need lots of oil to keeep a good piston ring to cylinder wall seal.

    Ja22, as unior says, mix your fuel and oil in a separate container. Never mix it in the fuel tank.

    Regarding types of oil, it seems to be most recommended to use mineral-based, (non-synthetic), oil during run-in, then full synthetic oil afterwards. Not sure of the reason. Maybe someone can enlighten us on this.
    Last edited: Sep 22, 2010
  5. HeadSmess

    HeadSmess Well-Known Member

    personal choice.... i run a 40:1. guesstimate. one mix for everything...chainsaws etc. call me lazy.

    gotta love the smell of castor based gokart oil :) too expensive though...

    i just use the stuff at the hardware.

    thrash the lil beast n it just keeps getting better...

    and at the price, couldnt care less if it blows up... :)

    (now over 4000km)
  6. HeadSmess

    HeadSmess Well-Known Member

    and i think the synthetic/mineral deal is to do with hi temp viscosity. mineral is thicker, so more protection while lousy chinese surface finishes "lap" in....

    breaking in an engine is akin to lapping, and i do was the only time i went overboard with the oil.(about 10:1) its there at that point to flush all those lil metal particles out.... the exhaust! 2 strokes are horrible :p

    theres also something about using watercooled oils in aircooled engines is a no-no... they arent designed for such hi temps...