Hope you don't mind but I'm just going to copypasta something I posted elsewhere about turning up the injector pump... It was written referencing the directions posted on Flash Offroad.
First, it mentions a small mirror. You'll definitely need one. Almost impossible to see the hole otherwise. Also, you would do very well to get one of those claw things like this:
You will drop parts into the engine valley and that is the fastest way to get them out.
The directions mention removing the throttle cable bracket mounted on the pump to access the cover plate you need to remove but, they don't mention what a pain it is getting to the 5/8" nut that holds it on at the bottom and how it is nearly impossible to get that nut back on. It is very tight confines and with the bracket's design, you can only take it off and put it on with the nut completely removed because of the slotted mounting hole on the bracket. I figured out if you open up the hole by removing the bottom part of the slot, you can leave the nut on the stud and just slide the bracket onto the stud. Here's a shot of the bottom of the bracket before I removed the small part at the bottom of the slotted hole:
Made reinstallation a lot easier.
The screws on the cover plate are 1/4" hex head. I found a regular wrench was the easiest way to get them off. The throttle on the pump is too close to get a socket in there and it is too inset in the valley to get a screw driver bit in there.
Once I got the cover off (tedious because of how little wrench movement you get), I stuck the small mirror into the valley and had a perfect view into it. I got very lucky and my adjustment screw was exposed without having to turn the engine any.
The directions mention a couple different sizes for the allen wrench you use to adjust the fuel but I can confirm it is 5/32. I found with my allen wrench that the short leg of it was too short to get to the screw and the long leg was too long to fit into the valley. Used a Dremel and trimmed the long leg down until I had clearance.
The directions mention turning the screw clockwise to increase the fuel. That would be clockwise if you were looking into the access hole directly, counterclockwise if you're looking into the mirror from the opposite side.
Because of the tight confines and how tight the screw is initially, it is really tough to turn with your fingers. I used a set of channel locks. Once it was freed up, it was a bit easier to fine tune.
So yeah, unless someone has a better recommendation, you'll have to use an open ended wrench on the access cover screws and it
slow and tedious. Partly why I haven't gone back and adjusted the pump further.