old dog still not running right

ZOOMCAT

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Mar 14, 2008
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i would like to thank everyone for there help. my old dog 70cc bike stop running about 2 weeks ago i bought a new cdi and new carb the problem is it will start and runs good but when i pull in the clutch it just dies and when i start it and pull the thottle it just sound like it's missing. the carb is ajusted right but still does not have the love it did berore it stoped running. thanks. zoomcat:confused:
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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i would like to thank everyone for there help. my old dog 70cc bike stop running about 2 weeks ago i bought a new cdi and new carb the problem is it will start and runs good but when i pull in the clutch it just dies and when i start it and pull the thottle it just sound like it's missing. the carb is ajusted right but still does not have the love it did berore it stoped running. thanks. zoomcat:confused:
You mean it won't idle - because you say when you PULL the clutch IN it dies. Set it 4-41/2 turns. Sounds like maybe an air leak....

So what does your spark plug look like? Are you trying a new plug?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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Will it stay running if you keep the throttle partly open? Turn the idle screw in a lot more.
Missing? is it way too rich and firing every other time sounding like a machine gun instead of a purring two stroke?

What color is the plug? White (too lean) Black and oily? (too rich)

How many hours on the engine? is it just worn out to the oint that the compression is too low?
 

ZOOMCAT

New Member
Mar 14, 2008
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i was just wondering if it could be the ignightor inside the motor. i cut the kill switch wires to see if it was a grounding thing. but still is dying every time i pull in the clutch. and does not idel. when the motorbike is going down the street it works great. thanks. zoomcat
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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I would venture a guess that your idle screw is either worn or maybe the slide is worn where it sits on the screw. You have tried turning the screw in a few turns haven't you?

If it's running good when you are on the gas and running down the road, then it is not an air leak, unless it's running really hot.
 

ZOOMCAT

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Mar 14, 2008
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:ride2:thanks bikerguy joe. the carb is brand new i kept messing with the idle screw turned it in got it to idle. but once around the block it just seems to die. where should the cable ajuster be set because i'm cluess on that. thanks..zoomcat
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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up north now
Maybe the screw is backing out? They have been know to wear rapidly too.

You should only use the cable outer for adjusting free play in the cable. Loosen the bigger "nut" or thumbscrew, then screw in (tighten) the thinner hex shaped part (cable adjuster) the cable rests on until there is a minute (1/32th inch) amount of play between the cable outer and the cable adjuster, tighten the thumbscrew.