(80/66cc) just bought a motorized bicycle.

Discussion in '2-Stroke Engines' started by zoomingbuddah, Jun 4, 2016.

  1. zoomingbuddah

    zoomingbuddah New Member

    I recently bought a motorized bicycle ive been enjoying it so far however i have had some problems already.
    The tube ends(2 and 4) have came off and spilled alot of gasoline. which could have been a big problem if it went unnoticed. When i was first trying to get it going i had to mess with the fuel thing (3) to get it going, even though i didnt know what i was doing since the writing was in chinese.

    So i have two questions. Is there anything i can buy to make the tube ends(1,2,4) more secure so they wont come off?
    2nd. how exactly do i use the fuel thingy(3)? what position is it currently in?
    resized motorized bicycle number n arrows.jpg Thanks for any info.
     

  2. Hello Moto!

    Hello Moto! Active Member

    Your fuel thing or petcock is in the open position. When the lever is inline with the tube it is flowing and when its at a right angle to the tube it is off. For the fuel line issue you are having, you can get fuel line clamps. What I do though is run 3/16" inner diameter tube rather than 1/4" for a tighter fit. I also use little fuel line clamps for added security.
     
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  3. Hello Moto!

    Hello Moto! Active Member

    oh man by the way, you really want to get an air filter for your carb lol
     
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  4. crassius

    crassius Well-Known Member

    your petcock lever (3) is in the on position (aligned with the flow), one should always keep it in the off position (perpendicular to the flow) whenever the motor isn't ready for starting

    the fuel line there at the filter (2, 4) can easily be tightened with a small hose clamp - the fuel inlet on carb (1) is a tight space and often only some safety wire wrapped around it will fit in there
     
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  5. jaguar

    jaguar Well-Known Member

    buy a lawn mower foam filter and make it work. Without a filter the engine will breath in dust which will wear down the engine bearings and groove the cylinder.
    use small zip ties on the fuel lines.
     
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  6. Hello Moto!

    Hello Moto! Active Member

    Check out the pic for reference.
     

    Attached Files:

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  7. Hello Moto!

    Hello Moto! Active Member

    Man that motor is really crammed in there lol. Your carb looks like it doesn't quite fit and is at an angle o_O
     
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  8. zoomingbuddah

    zoomingbuddah New Member

    @HelloMoto! Yeah that's what I thought when I bought it but it was my 1st motorized bike so I didn't know better.
    Thanks for the air filter tip, It always looked like something was supposed to go there lol

    @HelloMoto! @crassius so when I'm not using it leave the petcock lever perpendicular to the tube and when I'm going to use it align it with the flow? Would I leave it perpendicular when I just ride it as a regular bicycle?

    Thanks for the hose clamp suggestion gonna head out and pick some up
     
    Last edited: Jun 4, 2016
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  9. Hello Moto!

    Hello Moto! Active Member

    Correct. Anytime you're not using the engine leave it perpendicular or at a right angle. That is the off position.
     
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  10. zoomingbuddah

    zoomingbuddah New Member

    @HelloMoto! Alright Thanks for clearin that up for me

    @jaguar how exactly would I go about installing it specifically? Because it didn't come with thecap
    Would I just buy a foam filter and use two zip ties to hold it against the carburetor? Or what?
     
  11. jaguar

    jaguar Well-Known Member

    use whatever will work, just to make sure the air is being filtered. I used a large hose clamp.
     
  12. Hello Moto!

    Hello Moto! Active Member

  13. Hello Moto!

    Hello Moto! Active Member

    You'll probably have to work something out with a foam filter like jaguar suggested because I don't think you'll have room for the stock air filter. That's probably why there wasn't one on it when you bought it. It wouldn't fit so they took it off!
     
  14. crassius

    crassius Well-Known Member

    yes, turn it off whenever motor is not running - the carb float is supposed to turn flow off when carb is full, but often fails due to angle bike is at when on kickstand or hitting a bump while just pedaling - if not off, then the motor may fill up with fuel and be VERY hard to start again
     
  15. Steve Best

    Steve Best Active Member

    Here is what your cylinder will look like if you ride without an air filter:

    [​IMG]

    I was using the stock air filter but riding on sandy trails. The stock filter is not up to the task.
    Here is what I am now running:
    [​IMG]

    [​IMG]

    This is a plastic jar cap with a copper pipe glued into place with epoxy putty.
    The plastic water bottle neck was heated in boiling water to make fit.
    The foam is a kitchen "scrubbie". Make sure you can breath through it, some are more closed cell.
    Notice the pipe is centered with the carb throat.

    Also notice the twisted wire "clamps" on the fuel line. 2 wraps will keep it sealed tight.
    [​IMG]

    Steve
     
  16. Frankfort MB's

    Frankfort MB's Well-Known Member

    Guess I better run an air filter:)
     
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  17. Steve Best

    Steve Best Active Member

    Ha! And a darned good one too!
    Hey Frankfort, I'm still running this cylinder until it dies. What have I got to lose?
    Although I do have a good filter on it now. Did about 50kms of dirt trail today, much of it deep fine sand.
    Nice to have a good filter and the high torque head on to power through that stuff.
    Jeff gave me the idea to bring the "High Torque" air filter (Perrier plasic water bottle!) along for these conditions.

    Steve
     
  18. Frankfort MB's

    Frankfort MB's Well-Known Member

    I just ride on the road but they are back roads that are very dirty and bumpy. I need to rejet my bike so the only way I can get it not to 4 stroke is without the air filter...
     
  19. jaguar

    jaguar Well-Known Member

    I didn't realize the stock one did such a poor job. But I suspected it was crap at the very first so I cut up and glued together a lawnmower foam air filter because oiled foam is what I was used to from riding dirt bikes (motorcycles).

    ps- Steve, my first bike was a Penton 125 which was kinda the forerunner to the KTM. (After that a Honda XL250, then a Husqvarna 125 that I raced about 10 times in Austin)
     
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  20. Steve Best

    Steve Best Active Member

    Yeah, I suspected the stock filter was crap too, but hey, "they gotta know what they are doing", run with it I figured.
    Worse than a K&N. Never, ever use a K&N if you are running in the dirt, unless you are going to pull a serious filter over it.
    I've been disappointed to find grit on the inside of my intake after using K&N.

    Saying that, the gauze filters are probably fine for street use if well oiled. I'd like to hear some opinions.

    The Penton is the grand-daddy of KTM. I took a long road to get here.
    67 Honda Dream, 74 XL250, 74 CR250, 76 DT250, 78 XL500, 85 XT600, 87 DT200.
    Owned a lot of short timers too, including a Kawi triple. Bought the EXC125 slightly used in 2000 and love it.
    I have a 2003 300EXC but love the 125 for the ride. The 300 is actually lighter but feels heavier.
    A friend of mine has a Huskie 125 (2000?) that I ride. Nice bike. My KTM has broader power but the Huskie feels lighter.

    Good advice, ditch the stock foam. Install something better.

    Steve
     
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