Engine Always Starts, But No Power

Discussion in 'Motorized Bicycle General Discussion' started by VaporKing, Jul 11, 2008.

  1. VaporKing

    VaporKing New Member

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    Hi Everyone.

    I have a "65"cc ThatsDax engine that stopped working the next day after a 50 mile trip (about 2 months ago). Someone from this forum, in their wisdom, advised me to tighten my clutch plate, after I reported that there was no apparent compression on the engine.

    IT WORKED! I disengaged the clutch plate, turned the flower nut clowise one full rotation (as far as it would go by hand), and now the engine fires. Whoever helped me, thanks for your help! I'll look-up your handle when I have the chance.

    Now, I have a new problem.

    The engine now always starts when I want it to, but I can't get any power. When I turn the throttle handle, there is little, if any effect on the power. Upon inpsection of the throttle cable, it appeared to be loose (still trying to figure out why this cable started flopping-around). I retightened the cable, and it still doesn't give any power. (Shouldn't the throttle handle spring-back to low independently, without helping it). I removed the needdle/barrel assembly, reinstalled, and still no power boost. Just still get a very reliable start, with no power. I can hear/feel the needle changing position inside the carb while turning the throttle handle.

    Do you think that I need to port my carb, like BaconTeeth did? I know that he clipped his needle to run more rich, but nothing happened until he re-ported the intake manifold. If this is probably the solution, then why did my engine run OK before the 50 miler?

    Or am I still way off track?

    While my bike was working before, it would start on the first try easily, but after the first cold start, it start only with a lot a difficulty (probably flooding, even without choking). It would be nice to be able to retain the reliable starting action that I now currently have, while also fixing the power issue.

    I'm ready to mutilate, or "ream my carburator a new out-hole". Whatever it takes.

    Thanks for your help.
    (c)
     
  2. misteright1_99

    misteright1_99 New Member

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    It could be that the throttle broke inside, they are plastic, Take it apart and look.......
     
  3. VaporKing

    VaporKing New Member

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    Thanks for the response.

    I inspected the throttle handle assemby before posting my original request. The assembly is intact, but the cable doesn't spring-back automatically. I'm not seeing any kind of spring in the throttle handle; perhaps the spring in the needle-barrel assembly is intended to actuate the handle back to low "on its own".

    I'm going to "goose" the carb needle assmbly by hand (while running) when it gets light tomorrow. I know that this probably will not work. I'm not doing it in the dark, or else my neigbors would wonder if I lost my faculties.

    Obviously, I'm no expert, but I'm having a hunch that I'm running too lean, and need to get more gas into combustion. I was getting better than 150 miles/gallon before the issue arose.

    But who knows, perhaps I'm completely not seeing something, like not knowing what a loose clutch plate feels like. :)

    I'd appreciate any responses.

    (c)
     
  4. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Check for proper throttle operation visually. The slide might not be goin back on it's own because sometimes they are a tight fit (I had to sand one of mine for a half hour before it would even MOVE).

    Check to be sure the needle clip is at the second from the top on the needle.

    I'm thinking you have the dreaed air leak, fire up your bike and spray some WD-40, water (from a spritzer bottle) or carb cleaner around where the carb clamps to the manifold, and where the manifold bolts to the engine. if there is ANY variance of rpm, you have an air leak. Re-seal the manifold to the jug (cylinder) with some Seal-All or RTV sealant.

    Let us know what you find.
     
  5. misteright1_99

    misteright1_99 New Member

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    Well my carby wouldnt spring back last night on its own only to find that the plastic inside the throttle that holds the cables barrel end had cracked. The spring is inside the carb, under the cap above the slide.....
     
  6. VaporKing

    VaporKing New Member

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    You all have been great with your assistance!

    I finally had a day off, so I could submerge myself into this problem.

    I had time to do a little research on two-stroke engines. Given that 3 things are neccesary for motor operation (compression, fuel supply, and spark), I worked on ruling everything out. I had spark, and compression, so I knew that fuel delivery had to be the culprit.

    I've taken-apart carburators before from old cars, and never have been consistently sucessful on getting the car to work as desired afterwards, so I had very little confidence that this tear-down/reaasembly would be sucessful.

    Norm's "Total Carb Breakdown" gave me the initial interest on what to do. I was also fortunate enough to be able to speak with Duane from ThatsDax, when he gave me confidence tear-down my only carburator on hand, by emphasing the simplicity of its design. I was relieved to see that I had all kinds if "junk" in my carburator, in both the needle-seat and jet, along with other stuff sitting in the bottom of the bowl. (Wormy bugars).

    I ordered a shelf carb from ThatsDax, in the event of unsuccesful cleaning. (I had nothing to lose at this point).

    A word to the wise: Always install a good inline fuel filter before starting-up for the first time. I purchased my bike used, with a dirty carburator, and it gave me all kinds of trouble. I was very confused, trying to blame everything from the CDI, to the throttle assembly.

    I disassembled the whole carb down to the last screw, and blasted everthing-out, from head to toe, with Gumout carburator cleaner. Duane emphasised the important stuff to watch for, like being able to see a nice, clean tunnel through the jet and needle seat assembly. )By the way, eye protection is highly recommended when blasting the ports/jets with the plastic straw.)

    A see-through fuel line, and fuel filter made it easy to verify proper fuel delivery. The tickler was also very handy for refilling the bowl. I'll bet that's the only purpose for the tickler button.

    After cleaning-out the carb, installing a new inline fuel filter (Briggs and Stratton), and flushing-out my tank, I knew there was no way that engine could fail now. All three elements: compression, spark, and fuel delivery were present. I told my daughter to plug her ears (muffler-off), because there was going to be some loud popping about to happen in the basement. Sure enough, that baby fired right-up. (default clip setting [2'nd notch], and 3 turns-out ffrom full seat for the idle speed needle).

    It now starts whenever, hot or cold, and wherever I care to. I'm no longer fearful of turning off my engine, for fear of having to spend a mile or so restarting it.

    Thanks to Duane (ThatsDax), and Norm, for the pictorials. I'm kind of liking this hobby, and now new hope is restored for realizing a savings from the 150 miles/gallon savings for commutes.

    ThatsDax highly recommended!

    Sincerely, VaporKing
    (c)
     
  7. stude13

    stude13 New Member

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    hi; you did good. with your confidence it is possible to fix a lot of things. if something is broke or not right, look it up on the web. you can save a lot of money. parts is parts
     

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