Why do 2 stroke motors run different ratio's of oil in the fuel mix

Discussion in 'Motorized Bicycle General Discussion' started by ride65, Oct 6, 2009.

  1. ride65

    ride65 New Member

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    Some 16:1 40:1 50:1 depending one the motor. what is the reason for some to need a richer mix then others?
     
  2. bandito

    bandito New Member

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    It seems to me the oil ratio mix is in direct proportion to the owners ego!
     
  3. donuts31

    donuts31 New Member

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    Ignorance by both manufacturer and owner.
     
  4. BarelyAWake

    BarelyAWake New Member

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    Well, if yer talking about different brands and type of motors than just our chinagirls - much of the variance in manufacturer's recommendations has to do with that specific engine's machining tolerances, operating RPM range, and application.

    If yer askin' bout just our lil bike motors - depends on what the owner is willing to experiment with. The manufacturer's "16:1 & 20:1" recommendations for our bike may in fact include the possibility of using standard (read low-grade) motor oil instead of 2 cycle, but these are sloppy lil motors that may or may not need a lil extra lube... but therein lurks a debate lol

    I'm quite happy running 36:1 with Amsoil's synthetic "50:1" but some are of course running the 100:1 stuff at various ratios... it's up to you :D
     
    #4 BarelyAWake, Oct 6, 2009
    Last edited: Oct 6, 2009
  5. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    I use regular 2-cycle oil, & break in the engine with 24:1 mix. After the break in, I use 32:1.
     
  6. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Venice got those instructions from me. ;)
     
  7. xlite

    xlite New Member

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    Environmentally conscious individuals will use 50:1 or synthetic 100:1. Others need to leave a trail behind so they won't get lost so use more oil. :)

    FYI more oil in the gas results in a leaner mixture, not richer.
     
  8. FlyJSH

    FlyJSH New Member

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    So what is the correct ratio if I use Crisco?
     
  9. BarelyAWake

    BarelyAWake New Member

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    1:1

    I wanna see pics tho o.o

    :D
     
  10. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I believe the OP meant richer as in "oil to gasoline".

    But, yes think about it....at 32:1 you have twice as much gasoline running through the jet than you do at 16:1.

    In honesty, I run 40:1 any more since all my other "goodies" run that mix.

    I have recommended 24:1 in the past because I have had a couple of Big Name sellers ask me to refrain from suggesting anything but 16:1 or 20:1 for warranty reasons, so that is sort of a compromise.

    So, for the record, run whatever you are comfortable running, and live with the concequences.
     
  11. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I do know that most of these engines are soooo loose that any amount of oil film is not going to make a huge difference. Oil film is only so thick, no matter what ratio you use.
     
  12. xlite

    xlite New Member

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    That pretty much sums up the situation and is best advice of all.

    Personally I think 40:1 is fine and generates almost no smoke. 16:1 and 20:1 guys really bug me though because they leave those black areas in my driveway. Grrrr.... dam chinese instructions!
     
  13. Fabian

    Fabian New Member

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    Oh yes, bandito really nailed this topic

    Quote: It seems to me the oil ratio mix is in direct proportion to the owners ego!


    After a lot of research and a topic i covered extensively in a previous posting on the internet, the ideal oil/fuel ratio covering a number of performance parameters, including longevity is 20:1

    That's it - with plain old cheap 2-stroke mineral oil, you will have good power and long engine life with 20:1 and this covers aspects of hydro/mechanical piston ring seal and good thermal management of high temperature locations in the cylinder.

    The other critical aspect for long engine life is "NOT" to rev the engine over 3500 rpm, regardless of how many people tell you that they rev their engine to 7500 rpm.
    Run wide open throttle as long as you like but don't rev the engine over 3500 rpm.

    Fabian
     
    #13 Fabian, Oct 13, 2009
    Last edited: Oct 13, 2009
  14. xlite

    xlite New Member

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    I heard it was IQ. If that's true 100:1 guys must be GENIUSES of the bike motor world.
     
  15. momentummotorgroup

    momentummotorgroup New Member

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    I use Opti-2. the you can find it at most mower shops. This stuff is simple. 1 packet to 1 gallon, for ALL two stroke motors. The guy at my local shop is stingy as he!!, and is still running mowers and motors that are years beyond their warranties off of this stuff. I have breathed new life into my older bikes with this, and just got done breaking in a new 66cc engine off of an initial tank of this stuff with absolutely no variance from the 100:1 mix. Ran like a champ the entire way through.

    It's my go-to choice from now on.

    Check out the LINK
     
  16. HoughMade

    HoughMade New Member

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    That's true, but I think using "rich vs. lean" for oil mix introduces a little confusion into the conversation. The terms "rich vs. lean" for fuel and air is the accepted terminology in the engine world. Perhaps we could use "more oil" vs. "less oil" instead of "rich" or "lean" when speaking of oil and avoid the confusion....but whatever- it ain't going to ruin my day if people ignore my friendly suggestion.
     

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