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Post by kyokyokyii on May 22, 2024 8:28:24 GMT -5
I have a 2021 taotao, 139qmb gy6 50cc with a 72bbk. I've done a complete top end tear down. Replaced, cleaned, checked (quadruple times plus some), torqued to spec, cleaned the carb(20mm), (88 main and 35 idle) re jetted the thing, cleaned it again, valve adjustment, oh yeah to eliminate fuel flow i put a on/off shut off valve.... blah blah blah... I'm new to this but I'm very meticulous and ocd. Plus also a few electric components... tight /clean connections and what not.... The stupid thing ram a new top speed and had some idle issues. Thought nothing of it cause she sounded clean, ran amazing better than she ever has... Now she is hard to start, won't idle worth a shh..... I'm so fed up at this point I'm about to use her as target practice ... . Anyone maybe have a clue..  Thanks...... |
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Post by FrankenMech on May 22, 2024 8:45:02 GMT -5
Go through the troubleshooting chart in the service manual. DO NOT skip any steps.
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sinfull
Scoot Enthusiast
Posts: 413
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Post by sinfull on May 22, 2024 12:40:36 GMT -5
Check and make sure the vacuum port on the intake is tight and sealed, if you can pull it off the nipple with finger pressure it not sealed and can cause the symptoms you are having
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Post by GrumpyUnk on May 22, 2024 14:01:24 GMT -5
IF you have checked fuel supply to the carb inlet, spark, good compression, and it still won't start, it could be the byvalve is not getting fuel, OR the idle is set too high, and you are trying to start on the middle range circuit.
It should start almost without any cranking if set properly. If the idle circuit is maladjusted, it will be hard to start. If the air supply to the byvalve is clogged it will be hard to start. Check the ports on the air cleaner side of the carb, those kind of spaced around the edge of the air horn. They must allow air through to mix for the idle, byvalve, and possibly pilot circuits.
I have adjusted the idle now and again so I could not get them started. Pull the byvalve and check that the probe is retracted. There is a little 'well' or chamber built into the float bowl. The byvalve probe to pick up fuel sits in the well. The well is fed by a pinhole that leads to the float bowl so fuel can slowly fill the well after startup. If clogged, you get no byvalve, and no 'cold fast idle'... Very difficult to start with it dysfunctional.
You could/can try twisting the throttle a few times to squirt some extra fuel into the carb prior to first start.
tom
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Post by kyokyokyii on Jun 6, 2024 17:55:12 GMT -5
Sorry for the hecka late update and reply.!!!
So I went back and undid everything that I could think of. Went back to what I remembered before I did the main mod.
Now she is running again!
Cx
You guys are awesome, I actually went down to the cylinder head and cleaned it up, made sure i was TDC, new gasket, put valve head on, redid the timing and all that comes with that. Torqued her back down. Opened my spark plug gap to .028 or whatever it was. Did my valves IN. .003 and EX. .004, new intake spacer
(Which I did find out exploded under throttle after I had done all that, but hey!, no leaking anymore or very very little which isn't noticeable if it is.) Also none of that spacer went into my intake.
Man.. that was.... welll......
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