This has a carburetor right? First check the choke it should open a bit as soon as
the engine srarts then continue to open as the engine warms up, after the engine is
warm it should stay open until the engine cools. If thats working you may have a
problem inside the carb like a bad needle & seat or float, I would bet on the choke,
you can prop it open also when working correctly the engine should fast idle when
cold and slow down when you kick it off fast idle or the engine warms up. Don't
add anything to your tank for water, all gas sold in the US contains 10% ethanol
that's more than enough to handle water contamination and is known to harm
certain carb parts like composite floats and I think you have one of those also. To
check that with the engine warm and the choke open look down the throttle bore
with the engine running if you seefuel dripping or running in you have a bad float. I
hope this helps you. Take care