You may have a blocked fuel filter... take it out and see if it shows signs of dirt or particles. The other likely culprit is your petcock, where the the fuel flows out of the tank and there's a lever to select fuel on or reserve. Take the fuel line off the bottom of the petcock, then turn the lever to "on". If you don't see a flow of gas out the petcock you need to replace or rebuild it.
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You may have a blocked fuel filter... take it out and see if it shows signs of dirt or particles. The other likely culprit is your petcock, where the the fuel flows out of the tank and there's a lever to select fuel on or reserve. Take the fuel line off the bottom of the petcock, then turn the lever to "on". If you don't see a flow of gas out the petcock you need to replace or rebuild it.