Oil-Gas ratios

Discussion in 'Motorized Bicycle General Discussion' started by Farthom, Jun 4, 2010.

  1. Farthom

    Farthom New Member

    Joined:
    May 16, 2010
    Messages:
    51
    Likes Received:
    0
    Alright, I have a grubee skyhawk 66cc angle fire engine, and the bikeberry.com manual that came with it says to use between 16:1 and 20:1 for engine break in, and between 20:1 and 25:1 thereafter. After reading a bunch of posts, I have seen lots of people recommending and/or using mixtures such as 25:1 for break in and 35:1 after. One post spoke of a mixture as lean as 40:1


    I have been using about 16:1 for break in, and am nearly complete. After I have used up this tank, I would like to know what mixtures I should/could be using. I'm somewhat new to this game, and don't know all the variables that come into play here. What I do know, is that the quality of oil matters. I asked the sales rep in an auto store for a good quality full synthetic oil, and purchased the following:

    PJ1 Goldfire Pro
    High RPM 2T 2-stroke oil
    50:1 synthetic blend

    This oil was somewhat expensive, so I'm pretty sure its a good oil. I don't know what "2t" means, or what 50:1 blend means. Can someone fill me in?

    Also can some of the veterans on here give me a yay or nay, on this motor oil, and some tips on what ratios I could be using?


    Thanks a bunch!

    Farthom
     
  2. Pablo

    Pablo Master Bike Builder & Forum Sponsor

    Joined:
    Dec 28, 2007
    Messages:
    3,658
    Likes Received:
    5
    a) it depends on the oil, indeed there are some oils that work at 100:1
    b) really no need for 16:1 during break in. I never have run more oil than 24:1, ever
    c) never heard of that oil, but they are saying it can be run at 50:1

    Mix up 25:1, and ride the bike and don't stress about it.
     
  3. Farthom

    Farthom New Member

    Joined:
    May 16, 2010
    Messages:
    51
    Likes Received:
    0
    How much can oil mixture affect engine performance?
     
  4. nolan_speed

    nolan_speed New Member

    Joined:
    May 31, 2010
    Messages:
    30
    Likes Received:
    0
    I'm pretty new to these engines but I've been running mine at 25:1 with Shell Natilus oil (that's what they had at the nearest gas station) and so far it's working fine. I figure that at 25:1 there is plenty of oil (most quality engines run 50:1) so the type probably doesn't matter nearly as much as if you're running an engine at the leaner ratios.

    If you run a two stroke without enough oil it'll make more power for a little while but you'll burn it up and the motor will be toast. If you run it with too much oil it'll make a little less power and it'll foul the spark plug. It's obviously better to err on the rich side.

    Maybe with your synthetic oil you could try splitting the difference between 25:1 and 50:1 and go for 32:1 or something? With less oil you'll make more power but you don't want to go with too little.
     
  5. Farthom

    Farthom New Member

    Joined:
    May 16, 2010
    Messages:
    51
    Likes Received:
    0
    What exactly is fouling a spark plug, and how can I tell whether I have done it or not?
     
  6. nolan_speed

    nolan_speed New Member

    Joined:
    May 31, 2010
    Messages:
    30
    Likes Received:
    0
    A fouled plug is one that is covered in oil and created a weak spark or no spark at all. When your plug is fouled the engine will be hard to start and will run like crap, especially at lower RPM, sometimes running the engine really hard will burn off the plug and it'll start working well again.

    If running it hard dosn't work, remove the plug and you'll notice that it's black an oily and will need to be cleaned or replaced.
     
  7. JG88cc

    JG88cc New Member

    Joined:
    Sep 22, 2010
    Messages:
    15
    Likes Received:
    0
    It would be a great idea to switch to a spark plus with a resistor at the end. They are made to prevent fouled spark plugs. I just bought a NGK BPRGKS.

    Not saying you shouldn't carefully mix your gas/oil (you really should). But its a good idea.
     
  8. Pablo

    Pablo Master Bike Builder & Forum Sponsor

    Joined:
    Dec 28, 2007
    Messages:
    3,658
    Likes Received:
    5
    Not sure who told you that, but it's not true.
     
  9. Shobiz1492

    Shobiz1492 New Member

    Joined:
    Feb 13, 2013
    Messages:
    25
    Likes Received:
    0
  10. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    4
    Looks like a generic two stroke oil for air cooled engines.

    What is the recommended ratio on the bottle?
     
  11. Shobiz1492

    Shobiz1492 New Member

    Joined:
    Feb 13, 2013
    Messages:
    25
    Likes Received:
    0
    it says up yo 50:1
     

Share This Page