Robert Bosch fuel pump

It is best to set the load screw (maximum delivery) on a dyno, as over-fueling will cost you as much, if not more, than not having enough!

If you feel that you still need to make "battle field" adjustments then:

Locate the approximate 2inch by 2 inch plate on the end of the pump, near the bottom. Remove the calibration wire(!) and the four cap screws with a 10mm (7/16inch) wrench. Inside, you will see a threaded rod with a jam nut. Using a screw driver (or whatever appropriate tool) hold the threaded rod stationary while loosening the jam nut. You will need to turn the threaded rod inward to increase fuel delivery! I would only turn it in 0.5 to 0.75 turns IN to start with. Re-tighten the jam nut while holding the threaded rod from turning. Re-install the plate and tighten the 10mm cap screws. You should run your tractor in a pull (or dyno) to evaluate power output and smoke level before making additional adjustments. It might be worth taking your pump to a reputable shop to have them not only set the delivery correctly for your engine, but they could also balance the delivery between cylinders and "tweek" your governor for fastest response. Sluggish governor action can also cost you precious horsepower and may be rob you of power more than inadequate fuel delivery volumes! It is certainly worth going in a talking to the people at whatever pump shop, as they can give you "the skinny."

Best of Luck,

Goldsburg