Re: 2002 nissan 8hp ?'s
What is your model? Year is unimportant for servicing, but precise model/serial is critical. I'm assuming you have an NS8B. The problem is likely in the fuel system. If your carb has a problem with the float and inlet valve, or if the fuel pump is weak, or if there is a restriction in the fuel line, or if air is getting drawn into the fuel system, you could be "running out of gas" at higher RPMs, even though there is enough fuel delivery for slower speeds. Yet it could be a number of other things. Grab a Factory Service Manual, available at any dealer, including me, and go through the motor in a methodical diagnostic process, paying particular attention to the fuel system.