Finally bought opti-2

Discussion in 'Motorized Bicycle General Discussion' started by fischer550, Jun 12, 2014.

  1. fischer550

    fischer550 Member

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    So I pulled the trigger and bought a gallon of opti-2 oil on ebay. Questions:

    1) Should I run in a brand new motor on 100:1 on this stuff, or use a different oil or richer?

    2) When running 100:1, do I need to put in a much smaller jet size than normal to make it rich enough?
     
  2. Davezilla

    Davezilla New Member

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    You can run this stuff at 100:1 safely, no problems there...
    You'll probably need to jet down a size or 2 to compensate for the higher fuel content in your fuel but start out with what you're running now and see how it goes... Always tune your jets from rich to lean and your engine will be thankful
     
  3. 2door

    2door Moderator
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    Lots of discussion here on the subject of break in using Opti-2. I and others do it and to my knowledge there have been no problems reported. Also there is no need to go heavier on the oil duing break in. I've seen some say to start with 80:1. I don't see the advantage to that.

    Put some miles on the engine before you start messing with jet size. Two to three hundred is suggested then go smaller in steps keeping a close eye on spark plug color and listen for signs of a lean burn (bogging at WOT).
    I personally don't rely on jet 'size' as sold. I've seen too much inconsistancy. Use the drill size, as has been discussed before. Drill sizes don't change depending on who's selling them. Jet sizes do.

    Tom
     
  4. crassius

    crassius Well-Known Member

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    these motors tend to be a bit 'lumpy' inside - I like a lot of oil for the run-in so the parts can smooth the lumps a bit rather than knock the tops off them
     
  5. mapbike

    mapbike Active Member

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    Post removed......... by me.

    Map
     
    #5 mapbike, Jun 12, 2014
    Last edited: Jun 12, 2014
  6. mapbike

    mapbike Active Member

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    I break all my 2 stroke engines in with what I plan to run in them which is Opti2 @ 100:1, I have no issues doing this and my engine run excellent and the rings seat in just fine after a few miles.

    Tom is spot on with how I think is the best way to get the jet size right, I don't buy jets relying on them to be the correct size, best way to know what you have is to solder and drill your own and then you know what you have and you can fine tune the carb just the way it needs to be for your area and fuel oil mix.

    Map
    .wee.
     
  7. mapbike

    mapbike Active Member

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    One thing I will add here Tom is that if someone only has the standard small packets of Opti2 available, those packets mix 1.8oz to 1 Gallon instead of 1.3oz per gal. this make the ratio roughly 72:1 I ran that mix for a while because I was buying the standard 1 gal mix packets and when I changed from that mix and switched over to running the 3.2 oz to 2 1/2gal packets, I didn't see much of a difference in my plug chops and didn't even change my jet sizes for the 100:1 mix since my engines still ran just fine and didn't show a serious rich condition, I figured since I run such long distances at high rpms that a little riched mix might be a good thing and so far it has been working great with no noticeable increase in 4 stroking with my bikes accept maybe just a tad at low rpms in a no load low speed.

    but now that I run the 100:1 I start them all off on it from the beginning and have had no problems.

    map
     
  8. fischer550

    fischer550 Member

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    My engine at my altitude is4 stroking so much at low throttle 2 door, that I'm really not gonna wait 200 miles before I tinker. I don't think it will hurt anything if I get her running properly from the get-go. The NT was not cutting it for me, I am putting dax carb on it now with about 10 miles so far.
     
  9. crassius

    crassius Well-Known Member

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    just finished first part of run-in on one - took just about 50 miles till it started climbing steep hills to suit me - I don't even bother to try hills after only 10 miles
     

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