Normally the 140 RX pump does not need any ajustment. So I would leave it be for the moment. After you have checked for crud in the places mentioned above, I would try the following:

Make sure you have an OS F plug fitted.
Make sure the low end screw has not been moved and is in the middle, verticle setting.
Try pinching the fuel pipe as you go to wide open and it starts to falter and then close the needle to give constant full revs, then back off 3 clicks.
Sometimes my 140RXs don´t like to transition to full revs straight away on the first start of the day so I end up just pitching the fuel line a tad and then they are fine for the rest of the day.
Take it easy for the first five flights and then set the low end screw lean about an 1/8, as per the manual and set the pipe length, as required. If its the OS Hatori check the manual. I use a Macs header and an ES Pipe that works great right out of the box :-)

Good luck, and keep posting here until you have it right.