100:1 Mix

Discussion in 'Motorized Bicycle General Discussion' started by Retmachinist, Jul 24, 2009.

  1. GEJoe

    GEJoe New Member

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    Any one want to buy my piston and cylinder that I had to replace from using Opti-2 according to instructions? Send me a message. I will use the rest of the Opti-2 that I bought up at the recommended mix of 40:1 and then buy no more. Fool me once, shame on you. Fool me twice, shame on me.
     
    #821 GEJoe, Jul 30, 2011
    Last edited: Jul 30, 2011
  2. rohmell

    rohmell Active Member

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    Did you contact Interlube (makers of Opti-2)?
    If their oil was in fact the cause of the failure, then they should pay for a new engine.
     
  3. GEJoe

    GEJoe New Member

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    I won't make you go back somewhere around page 64 of this thread, but yes, I contacted Brad about it and he dropped me like a hot potato. It seems that if you have problems with Opti-2, you are on your own, as it says on interlube's website. Fortunately, the Opti-2 fiasco only put me back about $30, and I did not follow Dax's instructions as to fuel to oil ratio. My bad.
     
  4. GEJoe

    GEJoe New Member

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    I will use a few tankfuls of fuel mixed with Opti-2 at Dax's recommended ratio of 40:1 so that I will still get what I bought the Opti-2 for in the first place - eutectics. Once the rings and cylinder wall are conditioned by the Opti-2, I will move on to a cheaper oil. I have found out on Auto-Rx Internal Engine Cleaner that American oil suppliers are allowed to fudge on stating that their oil is "synthetic". (Auto-RX is a really cool product that I plan to use soon on my 1999 Nissan Quest that has 285,000 miles on it and has just started to lose gas mileage and horsepower, does not work on two strokes, though). So on these little engines a break-in with the "eutectic advantage" would be more useful than using dubious synthetic or Opti-2 at the risky ratio of 100:1/72:1.
     
    #824 GEJoe, Jul 30, 2011
    Last edited: Jul 30, 2011
  5. Don P

    Don P Member

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    Humm i broke my 2 stroke ht in at 70:1 opti 2 not a problem. this was a new engine and i made sure that i had gas WITH NO Alcohol in it. Alcohol in your fuel is a death to a 2 stroke engine.
     
  6. GEJoe

    GEJoe New Member

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    I agree that alcohol is no good. You can go to pure-gas.org to find a station in your area that has 100% gas.
     
  7. GEJoe

    GEJoe New Member

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    The answer to the question as to why some two stroke engines seem to thrive on Opti-2 at 72:1 or 100:1 and why other engines overheat and seize on it as mine did seems to lie in two things: displacement to horsepower ratio and how the engineers took that into account when designing the engine's heat dissipating characteristics. China girl engines have two displacements and horsepower ratings and if I remember correctly the 48 cc engine has a 1.75 rating and the 66 cc has a 2.75 rating. So they would have a 27.4 and 24 ratio, respectively. My CAG engine that seized up was 47 cc with a 4.2 horsepower rating, a ratio of about 11.2 to one. A 47 cc engine that puts out 4.2 horsepower will produce more heat than the same size engine that puts out 1.75 hp. One of the factors that engineers look at is how much heat must be dissipated to keep the engine from overheating, and they take two factors into account with an air cooled engine: the surface area of the cooling fins and the cooling effect provided by the oil in the fuel as it passes through the engine. A higher horsepower engine, such as the CAG I have (which can produce up to 10 hp out of 47 cc), has a lot more heat to dissipate than the weaker china girl engines, and thus is more sensitive to the fuel to oil ratio and fin surface area. In addition, if the engineers kept the fin surface area down to make the engine more compact, they would be relying more on the oil to carry that excess heat at a specified fuel to oil ratio of anywhere from 20:1 to 40:1. When you raise the fuel to oil ratio above that you are in danger of making the engine overheat and seize the piston, as happened to me. Bottom line: follow the engineers' recommendations regarding fuel to oil ratio and you cannot go wrong. If their design relies too much on the oil in the fuel to dissipate heat and you reduce the amount of oil in the fuel, you may just experience a locked up engine. You could only find out the design specifications about a particular two stroke engine by contacting the engineers that designed the engine and getting a reply from them, or by trial and error as I did. Can we have the input from any engineers on this?

    1997 Associate in Applied Science - Automotive Technology, Cum Laude, Southern Illinois University
    1997-2003 ASE Master Technician
     
  8. Kristof

    Kristof New Member

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    IS this ok??? 75:1 mix, break in!!

    [​IMG]
     
  9. GearNut

    GearNut Active Member

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    That spark plug looks good for break-in.
     
  10. Kristof

    Kristof New Member

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    How about gap? Should I be worried about a gap?
    It is an NGK B5HS plug.
     
  11. BeaverRat

    BeaverRat New Member

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    Set your gap to 0.030 inches...
     
  12. Kristof

    Kristof New Member

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    How do i do that exactly? Do i have to buy the spark plug gap gauge and then force it to be .030 inches?

    Why is it supposed to be .030 inches?
     
  13. mapbike

    mapbike Active Member

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    Kristof,

    Just go by any auto parts store ( Autozone, Napa.....ect. ) and pick up a cheap spark plug gapping tool, only a buck or so.

    The width of the plug gap is critical for allowing the ignition spark to be at it's optimal strength for the best ignition of the fuel air mixture, if the gap is 0.020 it will produce a smaller shorter spark than a 0.030 gap, the gap is set based on the strength of the ignition system, if the gap is adjusted to say 0.050 then it will be too wide for the ignition/coil output strength of these engines and the strength of the spark will be reduced because it has to jump farther than it can jump and still be a strong hot spark.

    Hope this helps with the ?'s

    dnut

    Peace, map

     
    #833 mapbike, Aug 7, 2011
    Last edited: Aug 7, 2011
  14. Fulltimer

    Fulltimer New Member

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    Some gauges have a little notch cut in them. You put that notch on the piece that goes from the edge of the plug to the center and twist it to adjust the gap.

    I use a feeler gauge that has a bunch of metal strips with each marked with the thickness. You can used more than one strip if needed to get the desired thickness. Tap on the piece that goes to the center electrode until you have the desired gap.

    After you have done it once it becomes a piece of cake to gap a plug! :)

    Terry
     
  15. happycheapskate

    happycheapskate New Member

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    Yeah, just do it slowly and don't bend it much. If you bend the part too many times it will break off later, maybe in the motor.
     
  16. Goat Herder

    Goat Herder Gutter Rider

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    Here is an interesting article I found. Two Cycle Motor Oils I know this is cruel lol its as long as this threadlaff but there is interesting intellect in it.
     
  17. happycheapskate

    happycheapskate New Member

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    That is really interesting and relevant about how thicker oil can starve a motor for gas and possibly oil, too, if the carb is not re-tuned. This may be significant with the happytime NT carbs, as even a couple extra ounces of oil does make a noticeable difference to me. A lot of the people who are dissappointed with their motors on break in, using the thicker ratio, might be pleasantly surprised when the break in is over and the bike is getting more gas than oil, and runs a lot more pleasantly.
     
  18. GEJoe

    GEJoe New Member

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    Goat Herder's article explains what happened to my CAG bike engine. When I use Opti-2, it will be only at 40:1 to keep the engine from overheating and locking up. And yes, my plug was tan and run only on Opti-2 at 72:1. At the manufacturer's recommended ratio it is a good breakin oil to get the eutectic benefit. Then switch to something cheaper.
     
  19. DuctTapedGoat

    DuctTapedGoat Active Member

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    I pay the extra money to have the eutectic benefits all the time. The performance at good health is well worth the extra couple bucks to me.
     
  20. happycheapskate

    happycheapskate New Member

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    I tried looking up definitions for "eutectic" and got a voluminuous book of chemistry jargon.

    What does this mean, please, D T G? Do you mean the gasoline/fuel vaporizes faster and burns better?

     

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