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Discussion Starter #1
this past Saturday. my daughters bike was not running. well it was running but when you gave it some throttle it would die. I noticed on the fuel petcock it has a position that said prime. I put it there for a couple of seconds & now it runs great. what was causing this before? & how did this fix it? I will post photos soon. it really is a very nice bike.
 

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was her bike running ok before this problem started? was any work done to the bike recently?
 

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prime position bypasses the inside petcock spring and vacuum plug and allows gas to flow freely
 

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the way the petcock works, is when the bike is turning over and the petcock is in the ON position, and air flows thru the carb throat this creates a vacuum thru the vacuum hose from carb to the petcock which then this vacuum allows the spring inside the petcock to loosen and then the spring releases pressure on the plug thus allowing gas to flow to the carb bowl, when the bike is turned off and air stops flowing thru the carb throat, the vacuum stops and the petcock spring then pushes the plug to close the hole thus stopping the gas to flow to the carb, prime bypasses the vacuum plug and allows gas to flow with the motor either on or off
 

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What position was it in before you turned it to prime? When in the run position, it draws gas from about 3" from the bottom of the tank when running. In reserve, it draws from the bottom of tank when running. Prime draws from the bottom of tank whether running or not. Its possible it is just low on gas if it was in the run position. There are 2 hoses on the petcock, the larger hose is gas, the smaller is the vaccum Btom mentioned. It goes to the top of the carb as you look at it mounted on the bike. If it is cracked or not on properly at either end, you may not get enough vaccum to open the petcock. Try starting it in the reserve position. If it runs ok, try filling the gas tank.
 

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Discussion Starter #6
sorry about being so long answering. yes it was running fine before this event. no work had been done either. I did take it to the gas station & I only put 2.5 gallons in it. not sure what happened but its been running great every since.
 
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