The factory Rhino carb can only handle between 2-3 psi. Are you sure it was vapor locking when you had the factory fuel pump connected? Here is what I suggest: Reconnect all the factory fuel pump and lines, and then run it until you experiance the same issue again - then disconnect the fuel line from the carb and crank the motor. If fuel comes out, then the factory vacuum operated fuel pump is working and you have another issue. I have seen aftermarket CDI boxes cause the same type of issues when they get hot or cold.

Some other things to check:

*Fuel pickup tube for any cracks or anything clogging it (I seen plastic and other items in them)
*Gas cap (make sure it has the vent installed)
*Tip over valve (located behind the fuel pump) - if it is clogged or stuck close it could cause a vapor lock
*Vacuum line to factory fuel pump
*Fuel filter (change even if it is new - some cheap ones cause the same issue)(plus carry a couple of extras)

Finally, if it is the factory pump - Replace it with a factory one (they provide more than enough fuel for a factory carb - and you wont experiance the over fueling problems caused by an aftermarket electric pump.

Good Luck - and you might check out Mendoza's Offroad - they might have something you need.

Backwards!!