over reveving engine would not shut down after cold starting

Jinma 455 45/55 hp tractor would not shut down & RMP's shot sky-high as we started it cold. Thought it was electric senser but seemed to be putting out proper voltage. (THis was guessed since electrical diagram sux) Next we started to 'pull' the injector pump to send into repair shop. But we are stuck, yes can't 'pull' the gear wheel off & scared we might knock it out of allinement. We can mark it only don't know what size gear puller we need. Is there a part number for the main gear? Is there a receptive gear puller for that gear? I know we need to remount the injecter pump housing before we pull the gear. How much & where can we get a new pump & injectors? It might be better to have both (re-built & new one) and of coarse the most important is what gear puller type and model number.

ALSO need a good manual with electrical, the from Factory really is horrable incomplete and even have missing parts & wrongly labeled parts. Its the worst manual WE'VE ever seen! Its scary & sad! HELP!