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Discussion Starter #1
Here is how to do the petcock mod for the stock 49/47cc cags....

1: remove petcock from carb..
2: remove the small o ring from the bottom of the petcock
3: disasemble petcock
4: J-B weld the area where the white knob was
5: drill through the petcock where the fuel line is conected all the way to the bottom of the petcock where the little o ring was.(make shure you drill big enough so that you get good gas flow
6: put the little o ring back on the petcock
7: Put the petcock back onto the carb
8: install an inline fuel shut off valve

here are a few pics
 

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Sikk! I was going to do a thread about this. Saved me some time! Thanks CPP!
 

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Now I may be the only one out of the loop but what will this accomplish? Is it letting better fuel flow through the carb? If so, how?
 

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No the petcock jams all the time so using jb weld and a drill you make it stay open and install an inline cut off valve to turn it on, and off. Instead of turning the white knob you turn a cut off valve its much easier!
 

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No the petcock jams all the time so using jb weld and a drill you make it stay open and install an inline cut off valve to turn it on, and off. Instead of turning the white knob you turn a cut off valve its much easier!
it also helps fuel flow. if your engine is highly modified and requires more fuel the petcock will be restricting too much fuel, so by completely drilling through it you get better flow.
 

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Thanks for the answer fellas. Luckily this thread wasn't on the other day otherwise I would have done it instead of purchasing a two dollar fuel filter that fixed my problem, haha.
 

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Thanks for the answer fellas. Luckily this thread wasn't on the other day otherwise I would have done it instead of purchasing a two dollar fuel filter that fixed my problem, haha.

I would still do this mod or at least just leave the white knob on and use an inline shut off valve !
 

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Discussion Starter #9
no i do not think that will change much since the petcock itself is smaller thus restricting the line
 

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i fab'd a plate to cover the area where the knob goes, using the existing plate as a template and left the little holes inside. i used silicone gasket maker to seal it. bike runs good.
 

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Discussion Starter #12
yup and if you want more gas flow you can drill through bigger...
 

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Discussion Starter #15
I have to agree that some good thinking there fellas keep up the good work
 

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And, CPParent, if I've got this right, after the JB Weld has cured then drill through the tube openings on the petcock valve so there is continuous flow through? Does anyone have photos of the drilling process? I just don't want to screw this up or my sons will kill me.
 

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And, CPParent, if I've got this right, after the JB Weld has cured then drill through the tube openings on the petcock valve so there is continuous flow through? Does anyone have photos of the drilling process? I just don't want to screw this up or my sons will kill me.
yup after the JB weld has cured 24hrs. then get a dril bit thats the same size as the hole at the top then just drill it straight through on a drill press if you have one available. You really cant screw this one up
 

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Discussion Starter #19
yup thats right I use a 5/32 drill dont forget to take out the small seal at the bottom before you drill because it will rip if you dont take it off..
 
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