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Discussion in 'Motorized Bicycle General Discussion' started by deacon, Jan 22, 2008.

  1. bgoates

    bgoates New Member

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    Can't start

    I have purchased and installed the chinese kit (80cc 2 stroke) and can't get it to fire.

    I've done the following:

    1-double checked wiring connections...ok as per instructions
    2- tried a different spark plug
    3- sprayed starter fluid into clylinder..should have at least fired if there had been spark

    Any other ideas ? I'm thinking I got a bad coil but don't know how to test it ?

    Any ideas or suggestions ?

    Thanks
     
  2. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Remove the plug and put the wire on it and turn the engine over to see if you have spark.

    The kill switches on most of these are pure garbage, so I'd try removing that first.

    Also, check to make sure the wire is screwed into the CDI all the way and while you're at it, make sure the plug cap is secure.

    You can always shut it off with the choke or by just letting the clutch out with no throttle.
     
    #102 Bikeguy Joe, Mar 9, 2008
    Last edited: Mar 9, 2008
  3. Ilikeabikea

    Ilikeabikea Moderator
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    To test if your getting fire you can take the plug out of the head. With it still connected to the plug wire get someone to turn the rear wheel with the clutch out while holding the plug against the cylinder. If it's firing you will able to see and hear a spark...............
     
  4. deacon

    deacon minor bike philosopher

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    Ah when I had that problem on the first try I had a wire loose. My very first guess would be the wiring from the engine to the coil. So here is my suggestion. unhook the kill switch, then hook up the other to wires. and give it a try. Has directions on how to test the coil for spark in the classic instruction section.

    The other time I had this problem I did not have the coil wire attached to the coil end correctly. It takes some work to screw it into the little nipple that is inside the coil case. I didn't get it in good after I removed the wire for something else.

    Give those to things a try first, If it isn't either of those take a look here....http://motorbicycling.com/f3/troble-shooting-bicycle-engine-cdi-spark-197.html

    When I first installed my engine I was so apprehensive I thought everything was wrong and I wanted to trash it. It's take a little time but it will all work out
     
    #104 deacon, Mar 9, 2008
    Last edited: Mar 9, 2008
  5. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Re: Can't start

    Yes - check for spark.

    I'll bet it's flooded. Tell me how you assembled the carb, per the given instructions?
     
  6. deacon

    deacon minor bike philosopher

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    God I love this site.

    I had problems with my install and tried to get answers on the other site and it took days to get this many replies. Heck I never go this many if it hadn't been for Norman, I would still be pushing it.
     
  7. deacon

    deacon minor bike philosopher

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    When you figure it out be sure to let us know what it was. I am always having stuff go wrong the more I hear it from someone else the more I know what to do.
     
  8. bgoates

    bgoates New Member

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    OK....I've re-done the plug wires and put a different plug cap on and I now have spark but no fire.

    I'm pretty sure I did the carb per instructions, needle pointing downward through bottom of slide, washer inside slide, spring over cable, then cable through slit at bottom of slide and up through slide...and then screwed in place. I can't see anyway other way to do it. I've worked quite a bit on two strokes before and I'm plum out of ideas. It could have been flooded so I will let it sit overnight and see. Any other ideas.
     
  9. paul

    paul Active Member

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    mine did the same thing and i let it sit not because i was out of ideas but out of breath from pedaling lol. it ended up for me really simple. i gave it full choke and it fired right up. alot of people have said they never use the choke but i always have to or it will not fire
     
  10. deacon

    deacon minor bike philosopher

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    Full choke floods mine I use half choke and it firrs most everytime. My son in law showed me something for flooded engines. Take the plug out and burn it off with a cigarette lighter. Once the electrode is dry you can keep on trying. Just in case that helps any.

    If you have spark and you have gas, it has to be either the mixture or the choke which is the same thing I guess. You do have the gas turned on . I know that is insulting but hey I have done it. Ran out in traffic and burned off all the gas in the line and the engine died.

    Oh **** can you see gas in the line. Some of the guys have had takes so filled with crude the filter stopped up before it ever started. And did you prime the carb with the little button on the left.
     
  11. bgoates

    bgoates New Member

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    Thanks for your comments...I for sure have spark now. I suspect it is flooded but the plug doesn't look wet. On two strokes if you have fuel, air and spark they should work. I have spark, fuel is in the fuel line and I'm quite sure the carb is assembled correctly although it probably needs adjusting, and air shouldn't be an issue. So it has to be flooded.

    I will let it sit overnight and then try starting with no choke, 1/2 choke, then full choke.
     
  12. deacon

    deacon minor bike philosopher

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    plug should be wet. where is the needle clip set. It probably should be second grove from the top. Also take a small hammer or screwdriver handle and tap the bowl of the carborator. And yes if you have fuel air and spark you should be firing.

    a couple of things you should look at. take the carb loose from the manifold tube and work the throttle. You should be able to see the needle move down the manifold tube. If that is working you might have an air leak in the intake manifold tube. The safest way to stop that is to put some gasket seal around the tube before you slit it in the other part of the tube. I used an o ring but the gasket seal is safer the o ring could b sucked into the engine.

    If that is all good, then check your manifold gasket. A leak there could do it as well. If you try everything else take the bolts off and put sealer on the gasket both sides and reset it.

    I had an air leak and mine wouldn't start once. I made a new gasket from a cereal box but i put sealer on both sides. Keep us informed. We want to help you
     
  13. deacon

    deacon minor bike philosopher

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    I have been thinking and i bet you have an air leak in the intake manifold. That will give your fuel air mixture a fit. Use gasket seal, or an O ring, or even heavy bearing grease around the joint just to see if that is it then look on this site for a more permanent solution.. I have some rubber O rings that fit left over from a previous build. If the grease around the joint solves your problem, I would be happy to mail you one. You can slip it in at the end of your connection. If you don't want to wait, you can buy them the home depot type stores.
     
    #113 deacon, Mar 10, 2008
    Last edited: Mar 10, 2008
  14. bgoates

    bgoates New Member

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    Dumb question but I thought the choke was off when the lever was down. However, the following instructions from Powerking say
    2. Choke

    Have the choke set about halfway for starters. If it still doesn't start, move the choke lever closer to the top (off), and then start moving it lower. You will need to be at a speed of about 10-15km/hr before releasing the clutch.

    Other instructions I was reading said the down position was choke on.

    All I know after taking off the air filter is that when it is down the hole is blocked letting less air in so doesn't that mean the down position is choke on ?
     
  15. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    If there is a plate blocking the throat, then the choke is on.....all the kits I've had operate so that when you are choking the engine, the lever is in the "up" position.
     
  16. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    You may also want to try this since you have spark- remove the plug and turn the engine over several times to clear any excess fuel. Trickle a FEW DROPS of fuel mix in the plug hole and replace the plug.

    Give it a try and if it fires and runs for a few seconds that way, then quits, you are starving for fuel.

    Check to make sure you have fuel to the carb, and if after you confirm fuel is going to the carb, then I'd check for a manifold leak, either at the carb to manifold junction, or at the gasket where the manifold bolts to the jug- both places are notorious for leaking.

    One last thing- on one of my kits, where the carb has the splits/slots (manifold side) the slots were too deep and I cured that by running it on my belt sander until I ground off a 1/4", after that, it sealed fine.
     
  17. bgoates

    bgoates New Member

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    Ok..lets review. After tightening the plug wires and replacing the plug cap I do have spark. The clip is on the third ring on the needle. I have taken the carb off the manifold and can see the needle go up and down when I twist the throttle. I have bought sealant and sealed the carb and manifold junctions....I do have splits and slots which I may grind down. I have sprayed starter fluid in carb and cylinder at seperate times with no results. I have taken the float apart just to confirm the carb is getting fuel. I have tapped the float, cussed, chanted, prayed and performed indian dance. I have done everything I can think of except pee on it which is next. I have peddled my ass off trying to start the thing and have yet to hear even a pop out of it.:confused:

    Anymore thoughts ?
     
  18. bgoates

    bgoates New Member

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    Just thinking...even if I had a manifold leak would it not have fired when I sprayed starter fluid in cylinder ? This really has me baffled.....
     
  19. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Hmmm....

    Got good spark. (bullet connections, solid, right?) What is your gap?

    Lever up is choke on. You'll need full choke.

    Carb assembled correctly? ( The washer goes on top and use the second notch down on the needle)

    Wrong: Bad Manual

    Right: ttp://motorbicycling.com/attachments/f30/108d1202750711-motorized-bicycle-carburetor-install-rebuild-carbpict023.jpg
    http://motorbicycling.com/attachments/f30/92d1202749858-motorized-bicycle-carburetor-install-rebuild-carbpict004.jpg
    http://motorbicycling.com/f30/motorized-bicycle-carburetor-install-rebuild-302.html

    Lastly what you need to do now is take the head off and clean it well. Wipe the top of the piston and the cylinder walls off and allow the gas to evaporate. You probably have fuel preventing a good seal and compression. Put it all together with a new plug gapped at 0.020" and make sure head is properly torqued.

    It will start.
     
    #119 Pablo, Mar 10, 2008
    Last edited: Mar 10, 2008
  20. deacon

    deacon minor bike philosopher

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    gee whiz this is a bit of a mystery. When you drop the clutch does it make the compression sound or is it just nothing.
     

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