Engine Overrevving! Tryed changing carb and throttle cable. STILL DIDNT WORK!Help.

Discussion in '2-Stroke Engines' started by StrontiumEthics, Apr 29, 2010.

  1. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    My engine was working just fine last week. Then I havent rode it in one week. I made sure the petcock was closed, and choke was close before I leave my bike out for long period of time. Now today im riding it and it takes longer to start (Pullstart), and when I give it full throttle, and release it it just keep reving. When I release the throttle I keeps reving REALLY high, then a couple seconds later the RPM's go down. I thought it might be carb so I adjusted the idle screw. Still didnt change anything. Then I replaced the carb, and still didnt change anything. I am at wits end! What do I do now? It just keeps overreving, but it does idle but after a while it RPM's increase. What DO it do!
     

  2. motorpsycho

    motorpsycho Active Member

    it sounds like the slide inside the carb is sticking when you give it throttle.
    Remove the slide and make sure you have it in right. Line the slot in the side of the slide up with the pin in the carb. body.
    when the slide is inserted into the carb correctly, it will slide down to the botom of the carb. nice & easy with very little resistance.
    if the slide is slightly off, it will bind on the pin and cause the throttle to stick or not work at all.
    since you changed the carb,. and it is doing trhe same thing, i would double check the slide.
    sometimes a drastic change in temperature can also cause the slide to stick in the carb. due to expansion and/or contraction.
     
    Last edited: Apr 29, 2010
  3. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    LoL. Im sure that the Slide does stick I can feel it comming back down every time, and also Feel the pull on the throttle. When I insert it is does indeed have little resistance.
     
  4. Al.Fisherman

    Al.Fisherman Active Member

    If the piston is sticking, I've had that problem...I took it out and took some sand paper 80-120 and sanded it while rotating the piston, finished up with some 280...nare a problem since.
     
  5. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    I made a little type = ). I meant to say that it doesnt have any resistance when I put the barrel in the carby! It goes down quiet smooth. But I will double check again tommorow. I do have another barrel to cross check. However, I did use another throttlecable and it still didnt work the way it should work.
     
  6. Al.Fisherman

    Al.Fisherman Active Member

    In that case take the throttle handle apart and check to see if the cable is binding in the sleeve, check for kinks in the housing. Check that the throttle handle is free, and easy. When you took it apart did you put the spring back in?
     
  7. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    Yep I put the spring back in. But I think im gonna double check the whole throttle assembly. I know that IT HAS TO BE A FUEL Feeding problem. Either a serious Airleak, or maybe just the throttle. Have anything else in mind?
     
  8. AussieSteve

    AussieSteve Active Member

    StrontiumEthics, without the engine running, if you open the throttle then snap it shut, you should hear the slide hit bottom.
    Also, with the carb off, fit the slide without spring etc, tighten the carb top cap fully and try turning the carb alternately upside-down and right-side up. The slide should move freely.
    I had one carb that jammed on full throttle only when the top cap was tight. It must have distorted the carb body slightly. (I think that Ron, (Al.Fisherman), had the same problem.)
    I had another carb with a tight slide and had to buy another (third) slide before I got good throttle operation. Finally, mine works well and doesn't stick at all.

    Ron, mine are coated slides, so sanding isn't really an option. The coated slides sometimes have small dings, though, and need touching up lightly with very fine wet&dry paper before they'll move freely.

    StrontiumEthics, I meant to add - you would have been better off posting this in the appropriate '2-Stroke Engines' or '4-Stroke Engines' section.
    I'm assuming that you have a 2-Stroke HT engine, although everyone's advice above could apply to either.
     
    Last edited: Apr 30, 2010
  9. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    very interesting I will be checking it out soon. Possibly could happen.
     
  10. 210061741

    210061741 Guest

    The most common cause i found when my engines ever did this were as stated the sticking cabel.

    But a air leak will do the same thing.
    And it could be anywhere.

    Head gasket. you will see a little oil where the gasket is leaking on the bottom of the head. Pretty common.

    The base gasket allthough not common.

    And the seal underneath the magneto magnet could be blown.

    Most likly you would have some oil or nastyness under the mag cover.

    Check 4 an air leak.

    The carb leaks where it attaches to the intake sometimes too.

    If it revs high when you pull the clutch in and settels down after a few it's an air leak.
    If it revs and revs and revs the cable or slide is sticking.
     
  11. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    Ok so I replaced the carb barrel and the Overreving stoped but now. It doesnt even have any power AT ALL! Like No Torque, or topspead, I was going 15 and the engine sound like it was starving! I also opened up the magneto cover and there was NO Black oil. However there is like a black Sludge that is under the carb on the engine block. It was there for some time I just never really payed attention. Its very thick like waxy and very black. In the end the bike didnt start after a while... Ahh... problems. Any suggestions at this point?
     
  12. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    Also the gaskets are not leaking they are all fresh and brand new.
     
  13. AussieSteve

    AussieSteve Active Member

    When you say you replaced the carb barrel, I guess you mean the slide.
    Have you checked/replaced the spark plug?
    Have you checked to see that your cable is adjusted properly to get full throttle?
    Double-check your carb assembly.
    The sludge sitting on top of the crankcase probably means that your carb has leaked a little in the past.
    If you fit a new plug and run it until it warms up, you could check the colour to get an idea of what's going on.
     
  14. Al.Fisherman

    Al.Fisherman Active Member

    Do you know how many times "It can't be that...it's brand NEW" that I've heard? Remember this...Just because it's brand new it doesn't mean it's worth a d**n. Especially dealing with this Chinese junk. I say junk because it is compared to other countries products. Although I have minimum problems out of the ones I've built.
     
    Last edited: Apr 30, 2010
  15. 210061741

    210061741 Guest

    I would check and see where you have the slotted washer.
    On top of the needle e-clip or underneath the needle e-clip.

    It belongs on top of the needle e-clip.

    Also if you can flip the bike over with the plug out and rotate it a buncn.

    I've had my crankcase fill up with gas because of the carb leaking into it.
     
  16. 210061741

    210061741 Guest

    try to start it a bit and let me know if the plug is wet or dry.
     
  17. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    Ok Well. First problem. When I disassembled the carb I noticed something quiet strange. THERE WAS FUEL INSIDE THE FUEL BOWL. So there was fuel actually slushing around inside the fuelbowl! Not everything began to make sense. the float wouldnt rise and the carb would overflow and feed to much fuel! Once i changed the fuelbowl It ran like before except a little slower but I think its because of the fuel I mixed. And Occationally the same thing happened with the throttle but I think that is because the throttle slide gets stuck. I have to check that out some other time. I only got about 2 hours to play with it today. Any comments?Suggestions? Sofar. I am having the same prob but its not as reoccuring as the last time. It happens ONLY sometimes.
     
  18. Gh0stRider

    Gh0stRider Banned

    Isn't there supposed to be fuel in the "fuel" bowl?

    Or did you mean fuel in the float. That makes more sense.
     
  19. AussieSteve

    AussieSteve Active Member

    Which problem, flooding or slide sticking?
    If it's the slide, check it over visually for small dings etc and smooth them if necessary. On one slide, I found a tiny blob of the coating on the surface, making the slide tight. It worked perfectly after the imperfection was removed - it's the slide I'm using now.
     
  20. StrontiumEthics

    StrontiumEthics Motored Bikes Sponsor

    There was fuel inside the Float itself. It was pretty strange. First time I seen something like that. And Perhaps the slide is a little rough im gonna check it out. Get back to you guys in later on. Thanks.
     
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