2 stroke engine without an Air Cleaner

Discussion in 'Motorized Bicycle General Discussion' started by broHSI, Jul 29, 2009.

  1. broHSI

    broHSI New Member

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    Is anyone here running their Chinese 2 stroke engine without an air cleaner?

    Maybe you want it to look authentic and just have a venturi stack or a metal screen.
    If you are running without an air cleaner how long have you been doing it? and have you had any problems?
    Also did you use fenders when you weren't using an air filter?
     
    #1 broHSI, Jul 29, 2009
    Last edited: Jul 29, 2009
  2. Hot Wheels

    Hot Wheels New Member

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    I don't think it's a good idea, It don't take much to suck something in and hurt your motor.
     
  3. ~macaddict~

    ~macaddict~ New Member

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    I don't think running without an air filter sounds like a good idea. Eventually your bound to do damage to your engine. Be on the safe side and get yourself and air filter.

    ~Mac~
     
  4. broHSI

    broHSI New Member

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    Thanks for the replies.
    but i was looking for anyone that actually had run one of the Chinese 2 stroke engines without an air filter for a period of time.
    and to find out what happened.
     
  5. Cabinfever1977

    Cabinfever1977 New Member

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    i reccomend everyone use a airfilter,even thou i dont use a air filter all the time.
    i have fenders,thats the same as a mud guard.
    my engine still runs great(400miles on engine),but now thats its getting warmer outside here,my engine is bogging down at low speeds,but if i thottle it i can still cruise around 25-30mph.
    i think i need to adjust something.
     
    #5 Cabinfever1977, Jul 29, 2009
    Last edited: Jul 29, 2009
  6. MB-Monkey

    MB-Monkey New Member

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    cabin just a reminder i am sure but as the weather gets hot the motor does not suck in air as good. So now you nay have a rich condition going on. I would clean or change the plug and do some reads on it to see where it currently is. Also you may have a spark gap issue. Very minor things really.
     
  7. wheelbender6

    wheelbender6 Active Member

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    You could probably rig a foam filter inside a velocity stack, like the hotrodders do.
     
  8. Cabinfever1977

    Cabinfever1977 New Member

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    i think i may have added too much oil in my gas and i may just add some gas to thin it out.
     
  9. Retmachinist

    Retmachinist New Member

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    Wheelbender, You mean something like this? And for broHSI, I would never run one of these engines without an airfilter unless you were just wanting to know how long they would last without one.

    John
     

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  10. broHSI

    broHSI New Member

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    I love your stack air cleaner. Best one I have ever seen.
    Do you have a photo of how the foam is held in? and of the inside?

    How much to buy some off you?

    Thank you!

    I don't run these engines without an air cleaner which is why I am trying to find someone who has done it and to find out what the results were in some detail.
    how long did it last?
     
  11. wheelbender6

    wheelbender6 Active Member

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    That looks like the right stack.
    Velocity stacks usually have a screen mesh in them. You can attach a foam filter to the screen.
     
  12. Retmachinist

    Retmachinist New Member

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    The foam is 1" thick and held in with a press fit ring. The stacks arn't hard to make just time consuming. I would probably have to have about $20 if I was going to sell them. People usually don't want to pay much for after market parts since we get these engine kits so cheap.
    I guess that is why I make my own parts.

    John
     
  13. xlite

    xlite New Member

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    I ran for a short time w/wire screen instead of filter and got a little more power. I put it back when water got in the engine.

    One of the bikes I built for someone else was run w/o one for 600 miles at which point compression was so bad it didn't matter if clutch was in or out. Dust is like abrasive powder.

    Putting one in a velocity stack defeats the whole purpose.
     
  14. 2door

    2door Moderator
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    John,
    That's beautiful. Question: Do you notice any difference in intake noise and how thick is the foam. The 2 strokes are notorious for noisey intakes due to the, well, 2 strokes, and I've been giving some thought to trying BikeGuy Joe's idea of constructing a foam filled air box that would eliminate some of the pop-pop-pop that comes from the intake cycle.
    Tom
     
  15. matt167

    matt167 New Member

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    it would only take sucking up a small stone flung up from the tire to total the engine.. also, if you get water in the carb. enough could cause hydrolock, that's going to lock the engine up totally, which on a wet road, won't end well.. in the situation of water in the engine, the only thing you could hope for is that the water drained out the exhaust b4 it got compressed.. cause it'll bend the rod also
     
  16. Retmachinist

    Retmachinist New Member

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    Tom, The foam is 1" thick. I made a punch out of some stainless pipe and just punch them out. You get a little more carb, or intake noise. Kind of like the old Carter AFB's or an old Holley. Only on a smaller scale.

    John
     
  17. Nashville Kat

    Nashville Kat Active Member

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    I think most of the bogging down always described here is usually because of a rich mix, not fuel starvation , because closing down the petcock seems to help, but more oil in the mix is best.

    So to get a little more air, I drilled a few more small holes in the back of my standard plastic air cleaner. I'm not going to run in dirt or bad weather, and it still leaves the foam on the inside to filter out particles, and the outside plastic to stop anything bigger-
    the stock openings at the bottom seem a little restricting, don't they?

    and it seemed to run better- a small drill bit goes through the plastic like it's nothing, and you have to look closely to even see any difference
     

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