The best thing to do if you're doing any work that requires specific knowledge of settings such as injector pump timing is to get the service/parts manuals for your tractor and go from there. It's amazing the great information that is contained in these manuals and will answer all of these sort of questions for you and then some. There are a few places that can provide this. One is Sheaffer's Town & Country Tractor
When I bought my Iseki new I got the factory service manual at the same time and it has been very helpful except for the fuel system. The chapter on the fuel system is blank. It says to contact dealer. Just watch which one you get.
Most service manuals shy away from the injector pumps since you need some expensive and large special tools/instruments to work on them anyway. I noticed the service manual on the TSx series of tractors delves pretty deep into the service of the pumps but it really is irrelevent for the average garage mechanic due to lack of equipment.