Clutch and Throttle (problems?)

GabeOliver

New Member
Joined
Feb 3, 2019
Messages
4
I just built my brand new 49cc 2 stroke bicycle last week, and tried to ride it about half a mile. I'm really pretty sure it should be operating differently than this? what happens is the clutch DOes disengage and the bike rolls freely, until I let go of the clutch, and the engine starts just fine. but when I start going, it has a really high speed on it's own, before I even twist the throttle. the throttle does nothing. when I squeeze the clutch at this point, it just makes the engine revv up a lot until I let go, instead of letting me coast and use the brakes. please help? :) I'm sorry I posted this twice, but the first time I waited twenty minutes and it was never posted.... i could really use some advice, it's my first time doing this. thanks :)
 


Jag

Member
Joined
Oct 6, 2018
Messages
132
I just built my brand new 49cc 2 stroke bicycle last week, and tried to ride it about half a mile. I'm really pretty sure it should be operating differently than this? what happens is the clutch DOes disengage and the bike rolls freely, until I let go of the clutch, and the engine starts just fine. but when I start going, it has a really high speed on it's own, before I even twist the throttle. the throttle does nothing. when I squeeze the clutch at this point, it just makes the engine revv up a lot until I let go, instead of letting me coast and use the brakes. please help? :) I'm sorry I posted this twice, but the first time I waited twenty minutes and it was never posted.... i could really use some advice, it's my first time doing this. thanks :)
Make sure your throttle cable isn’t stuck up on anything and the cable moves when you twist the throttle, and make sure it is installed correctly to the grip and into the carb slide.
 

GabeOliver

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Joined
Feb 3, 2019
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4
well thanks, Jag, and hmm.... well, I can definitely see the needle moving in the carburator when I twist. maybe I'll reinstall the whole needle and spring though, maybe it's not all the way in there? ... that would make sense actually... is there a better way I could be able to tell if the needle is actually as deep in there as it should be?
 

Jag

Member
Joined
Oct 6, 2018
Messages
132
well thanks, Jag, and hmm.... well, I can definitely see the needle moving in the carburator when I twist. maybe I'll reinstall the whole needle and spring though, maybe it's not all the way in there? ... that would make sense actually... is there a better way I could be able to tell if the needle is actually as deep in there as it should be?
well thanks, Jag, and hmm.... well, I can definitely see the needle moving in the carburator when I twist. maybe I'll reinstall the whole needle and spring though, maybe it's not all the way in there? ... that would make sense actually... is there a better way I could be able to tell if the needle is actually as deep in there as it should be?
Which carb do you have?
 

MotorBicycleRacing

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Joined
Jul 3, 2008
Messages
2,241
I just built my brand new 49cc 2 stroke bicycle what happens is the clutch DOes disengage and the bike rolls freely, until I let go of the clutch, and the engine starts just fine. but when I start going, it has a really high speed on it's own, before I even twist the throttle. the throttle does nothing. when I squeeze the clutch at this point, it just makes the engine revv up a lot until I let go, instead of letting me coast and use the brakes. :)
You got an air leak where the carb goes on the intake which is making it revv up.
Put an O ring in the carb throat to seal it up against the intake.

And it is 48cc.
 

GabeOliver

New Member
Joined
Feb 3, 2019
Messages
4
Hey guys, you were both right, thanks a bunch! i just fixed the twist throttle grip, took it apart and put it back together and it was just a little bit not seated right. also I think there is an air leak, like u were saying, and it is getting way too much gas, leaking a little too much. at least the throttle actually gasses it now, and the clutch doesn't make it revv up a bunch. many thanks! :)
 
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