For those that have Montana tractors an issue can be that they slowly start to lose power and eventually get to where they will only idle. After waiting several days the tractor might start up and idle up fine but within 5 - 10 minutes the RPMs will slowing start dropping off. The first thoughts are either starving for fuel or sucking air. After you eliminate the obvious, replace old fuel lines, potentially clean the fuel tank, and replace the fuel filter, the injector pump is next (extremely expensive). What is not commonly known is that the injector pump inlet has another fuel filter that apparently few know about. The inlet connection consists of a banjo fitting. Remove the banjo fitting and then the connector beneath it. You will have to meticulously fish out the spring and then the plunger assembly and then you will see the top of a plastic filter. Carefully remove the filter and with it will likely come the piston assembly. The problem is very likely that this inlet fuel filter is clogged. Blow it out with air and put everything back, prime to eliminate air and chances are the tractor will spring back to life. Good luck!