Air in lines/carb issue?

Discussion in 'Motorized Bicycle Trouble Shooting' started by 1kbike, Sep 7, 2013.

  1. 1kbike

    1kbike New Member

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    I have a weird problem. I put bike together yesterday, and noticed the fuel filter was busted. So for the test start, used what gas was in the carb bowl. It started up. Fast forward today, put new filter on, turned petcock to "run" and no gas came out. Checked to be sure petcock was on and no blockage, still no gas. Checked fuel filter orientation that's good. Took gas line off after the filter and gas came in the tube and poured out. Put that back on and took off gas line at carb and gas came out. So, I think the blockage is at the carb? I don't know what the issue is and I don't want to tear into it with out some advice.
     
  2. 2door

    2door Moderator
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    Does the engine start and run? If so don't worry about what you see in the fuel line. Air, actually gasoline vapor bubbles in the line is common. If fuel flows when you disconnect the fuel line from the filter and carburetor there is flow and no problem.

    If the engine doesn't run then you might be looking at a float/float valve problem. Let us know and we'll go from there. We'll need to know what carburetor you have. And we're assuming you have a Chinese 2 stroke engine. Always give details when asking for advice.

    Tom
     
  3. 1kbike

    1kbike New Member

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  4. 2door

    2door Moderator
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    If the carburetor is getting fuel and the choke is open, assuming it is the NT carb, then you need to check your ignition.

    Remove the spark plug, reconnect the plug and lay it against the cylinder head and spin the rear wheel, clutch engaged. Look for a spark at the plug's electrodes.

    Tom
     
  5. 1kbike

    1kbike New Member

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    Here's a thought...Maybe I am not peddling fast enough? I admit, I wasn't the one who started it last night. I can't see at night so my friend started it. I didn't ask him how fast he went.
     
  6. 1kbike

    1kbike New Member

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    Ok, I'll try that too. Does it have to be spinning fast for it to make a spark?
     
  7. 1kbike

    1kbike New Member

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    Ok great news, I got it to start but when I pull the clutch (disengage) it dies. I am gonna go buy a new spark plug here in a few minutes to see if that will help. Also per instructions I had hooked up the kill switch like it said. Well, the instruction were wrong.
     
  8. crassius

    crassius Active Member

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    if you have not yet adjusted the idle speed, then you will need to hold the throttle open a bit to keep it running while you lock the clutch out, then reach down and turn the idle screw in until it runs on its own
     
  9. 1kbike

    1kbike New Member

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    It's ALIVE!!! LOL that's what it needed! I had to actually set the idle screw BEFORE I started it...it musta been WAY off. anyway, the bike said "take me around the block" so I did and it ran good, now gonna heat up the rings...It's running now outside. BBOL THANKS TO EVERYONE WHO HELPED ME!
     
  10. 2door

    2door Moderator
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    Congratulations 1kbike. We're glad you're on the road.

    Have fun and ride safe.

    Tom
     
  11. 1kbike

    1kbike New Member

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    The joy was short lived. The chain broke. Not sure how it happened but the idler pully came off, so when it got binded up the chain broke. Gotta order a new chain now. It was fun though. LOL At least I know it was more than capable of hauling me around. It was cool.
     
    #11 1kbike, Sep 8, 2013
    Last edited: Sep 8, 2013
  12. 1kbike

    1kbike New Member

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    Is there ANY other way to mount the sprocket other than those gaskets? I think that's what caused my chain to break. Looks like the chain rubbed on the spokes, grabbed it and pulled the pulley and everything else into it. The issue I've ran into with those gaskets is that they don't compress far enough to allow the sprocket and cruiser break to sit on. So, I took the front one off. Bad idea because I am certain that's what caused this failure. It was fun while it lasted though!
     
  13. 2door

    2door Moderator
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    What probably happened was the tensioner bracket rotated into the spokes. That is one of the most common mishaps to occur with a new builder. That bracket must be mounted securely so it can not move.

    As for the sprocket attachment to the rear wheel, did you install it correctly? It must be a sandwich. Sprocket, rubber, spokes, rubber, metal 1/2 moon plates. If the sprocket was against the spokes that is wrong. Much has been written here about proper sprocket installation. Do some reading, keywords, 'rag joint install'

    Also chain/sprocket alignment and chain tension are critical. There is a lot of information here on those issues. Search and read.

    Tom
     
  14. 1kbike

    1kbike New Member

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    Yeah, I pretty much did everything by the book except the extra gasket and not tightening the pulley properly. Learn as I go I suppose. Thanks for your help Tom. I'll try not to bug you too much any more. ;)
     

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