Hi All,
Rebuilding the injection pump is easy with the exception of the spring that holds everything together. If you are using WVO, it's my experience that you need to clean the injection pump once a year if your running the engine 24/7 or close to that.
The problem is that WVO is thick and tends to clog the injection pump drain hole at the bottom of the pump. The injection pump then gets sticky or sluggish, governor operation degrades, looking for all the possible solutions with out success and the injection pump is the only thing left. There are several directions on line on how to disassemble, clean and reassemble the injection pump. A vice or c clamp, socket, small screw driver, some wrenches and a bucket of kerosene is all you really need.
The other piece of information relating to this, I changed the injection timing from 18 degrees to 22 degrees and the amount of fuel noticeably decreased, carbon buildup rate decreased, injection pump gunk build up rate decreased. Speed regulation improved and engine is more responsive. The best part is that I don't have to tear down the engine every 2 months, more like 4 months and the job is much easier. The bad part about the 22 degree injection timing is diesel fuel does not run very well at all and you need to change over to WVO immediately. In warm weather, you can start on WVO. The amount of heat from the cooling water has also decreased which is tolerable since I can use an electric heater in the winter and cooling in the summer is much easier.
I hope this helps
sara