Turning up my tractor???

[BUCKS]

I have a case 4690 tractor and I'm looking to turn the power up on it.I had the fuel pump rebuilt a couple of years ago and ever since then it doesnt seem to have as much power. It is a bosch mechanical fuel pump, its not a p-pump but it does look alot like one. it has a cap on the back of it, with a plate on it. when i took that plate off there was a set screw in there. is this what I need to adjust? and if so how much?

 

[art]

I normally like to put a tractor on a dyno to check it's horsepower before I do anything to the pump.

I've also seen a small fuel leak that the owner said was not an issue take 100 horsepower from an engine!! Not bad that it was only 175 when fixed and the tractors original rating was--------125!