Starting a new engine on pure gas

Discussion in 'Motorized Cruiser Bicycles' started by WaterDog, Sep 19, 2010.

  1. WaterDog

    WaterDog New Member

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    Friend has a new build that wont quite turn over. Is it really bad to use pure 92 octane gas to get it started on idle for a minute and then add oil. We just cant quite it going mixed as low as 20:1
     
  2. corgi1

    corgi1 New Member

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    yes ,don't do it,the motor will be hurt,possibly ruin the cylinder and bearings,,,,some need choke to start others no or maybe some,,,spark,,,air leaks on the carb or manifold,,,,is the plug gapped right 17-20,,is it a new plug or the factory one,,,,does the slide go up/down when you look in the end of the carb and operate the throttle,,,,some others will have more suggestions
     
  3. The_Aleman

    The_Aleman New Member

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    Don't use straight gas on a 2-stroke, and I wouldn't advise using 92 octane on a stock Chinese 2-stroke, either. They are low-compression engines with no need for high octane. In fact, using 92 octane fuel can make a stock Chinese 2-stroke more difficult to start and can actually reduce the amount of lubricating oil left over after the power stroke.

    Things to check:

    Did you use the "tickler" on the carb to prime the engine?
    Have you removed the problem-prone fuel filter on the petcock?
    Is the ignition kill switch hooked up? These can easily short out!
    Doublecheck all wiring connections, make sure they are insulated well.

    The choke setting on these engines is relatively critical. If the engine won't even "catch" with full/near full choke, then it is possible that the coil or magneto are bad.
     
  4. WaterDog

    WaterDog New Member

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    Thanks, we will take a look. Hes a newby and so am I. Pretty much out of the box build with careful attention to detail, but I am sure some factory settings might be off..Its a zoom bicycle 66cc slant build and they are pretty good from what ive read here on the forum. Ill suggest we take caution to get it started. He got a really good downloaded manual so ill go through it. Thanks for the tip!
     
  5. momentummotorgroup

    momentummotorgroup New Member

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    I have had a few of the 66cc engines not want to start at all, one just needed a choke adjustment and the other actually had a pinhole in the tar paper gasket at the bottom jug. Wrestled with that one for quite a while before figuring it out.. Now I make it a rule to swap out the gaskets on them just because the stock tar paper ones suck. I use premium with opti-2 and don't have gas issues ever.
     
  6. bairdco

    bairdco a guy who makes cool bikes

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    quote from the Aleman: "Have you removed the problem-prone fuel filter on the petcock?
    "

    hunh? who has problems with that? i love that thing.

    as for the original question, NEVER run your motor on gas only, especially not the first start-up. your motor's been sitting around for a while with no oil in it at all as it made it's way here from china, and to "dry-start" it might just destroy it right off the bat.

    i actually dump a capful of oil down the plug hole on all my motors and work the crank before i even install them.

    if you're using a cheap oil, start off at 24:1.

    pull up the choke lever, push and hold the tickler button for a second, then get on and pedal your butt off. if it's trying to start, keep pedaling till it's actually running.
     
    #6 bairdco, Sep 19, 2010
    Last edited: Sep 19, 2010
  7. r00t4rd3d

    r00t4rd3d New Member

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    I bet the rings are torched. Brand new engine with no oil in the 92 oct gas and ran for a minute ?
     
  8. Drewd

    Drewd New Member

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    20:1 isn't needed on a new engine. 32 to 40:1 should be plenty for the engine.
     
  9. kipharley

    kipharley New Member

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    Pull your plug,is it wet?Did you unscrew the cap on the sparkplug before you put the boot on?Did the boot"zip" in place.What wires did you hook to what wires?When you peddled and poped the clutch did the engine turn over?Did it poop,fart,anything? Kip.
     
  10. Zack01GC

    Zack01GC New Member

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    Being in the landscaping business as long as I have, and my father fixing small gas engines on the side for many a year... I can tell you one thing.

    Either my boss or my dad would be very angry if I put straight gas in any of our weed-whackers, leaf blowers, or chainsaws. There's got to be a reason. I don't mean to sound rude at all, but it's the nature of the 2 stroke motor.
     
    #10 Zack01GC, Sep 22, 2010
    Last edited: Sep 22, 2010

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