Gramps,
The knurled knob on the injection pump is the handle for the priming pump. As Chris noted, you unscrew until it pops up a bit and then pump it like a bicycle pump to push fuel from the fuel line to the injector pump. You should only need to do this if you have run the tractor out of fuel somehow. If the "T" handle thing you have is actually a shut-off valve in a fuel line, you don't want to shut it off or you might inadvertently run the engine with it off and thereby lose the prime in your fuel system. A fuel shut-off in a fuel line (hose) is NOT the normal way to kill the engine. (Stay tuned for more on that.)
Your "injector pump assembly" actually has more than one section. There is the "lift pump" section that moves the fuel from the fuel line to the high pressure pump (the priming pump is part of this); there is the injection pump itself, which is the high pressure pump that moves the fuel under very high pressure from the injection pump assembly to the injectors themselves; there is the "governor section" of the system that controls the amount of fuel delivered to the engine. It does this by a system of fly weights that move a "rack" that meters the amount of fuel delivered by the injector pump. The tractor's throttle is connected to the governor section and adjusts the setting of the governor - increase the throttle and the governor will allow the IP to deliver more fuel up to a point - when that point is reached, the governor does not deliver any additional fuel. If the engine is bogged down, the governor will automatically increase the fuel delivery until the engine comes back up to the throttle setting.
Since a diesel has no "ignition" as such, the only way to stop one is to either shut off the fuel or shut off the air. Therefore, attached to the governor section of the IP assembly is a cable that pulls the governor rack back to a "no fuel" condition - this is the engine cut-off that you normally use to stop the engine. On my Jinma 304 that engine cut-off is located under the dash (cowling) on the left hand side - mine is a T-shaped black plastic handle like you would see for a hood release or some such on an older car. Yours may look different but is probably in somewhat the same location since this allows easy cable routing to where it attaches to the governor assembly. This cable is spring-loaded so you pull it out to kill the engine and then it springs back in so the governor can operate normally. The key switch on the dash only controls the starter and various electrical components, it has no function of stopping the engine on most diesel tractors.
To check the oil on your injection pump assembly you unscrew the little "mushroom-looking" cap on the top of it - this is actually a breather cap and the fill point for the oil in the injector assembly. Some pumps have a dipstick on the underside of that cap and others don't. If it does, follow the dipstick mark. If it doesn't, then there is a bolt that you remove to determine the "full" level - when it is full, oil will pee out the bolt hole. There are also one or two drain plugs on the bottom of the pump and governor assembly for draining the oil. It is a good idea to drain and refill the injector pump oil every six months or fifty hours of use.
If you have a digital camera, take a picture of the side of your engine showing the injector pump assembly and post it here. Then we can identify the various injector pump assembly parts for you on the photo. If possible, take photos that shows it from the top, side and bottom. If you can't post the photos for some reason, you can email them to me or one of the others and we'll help you. That's what this forum is for, after all. :thumbsup:
The compression release on my tractor is a metal rod lever located under the right side of the dash (cowling). It is grasped and rotated clockwise a quarter turn or so to release the compression. It does so by connecting to another rod that passes through the back end of the rocker cover and then connecting to a "treadle" in the valve spring assembly that opens all the exhaust valves at once. It is used to relieve engine compression to allow the engine to turn over more easily for starting in cold weather. Someone who has to contend with cold weather can describe the cold-weather starting drill for you - i live in the tropics and don' tdo that cold stuff.
Hope this clears some things up for you and makes your tractor experience a bit less frustrating.
Rich
