A stock petcock, with or without any modification is still a very poor stopcock.
It fails to give solid feedback when trying to find the "off" position.
Many times you may feel the ball go into the detente when turning the knob only to find it has nor stopped the flow but simply has slowed the flow!
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I agree Ricky, just trying to get my friend through until he gets the parts together to replace the fool thing. He wants to sell the bike but can't until this problem is fixed. I have a couple old OEM units and thought I'd convert one for him to use until parts come in.