Hi, i have a 4720 that continues to lose power and eventually stalls and is then very hard to start. A dealer told me it was bad fuel causing rust in the lines clogging everything. This has happend three times over the past two years and now again. They have drained the tank, lines new filter yet this keeps happening. I use fuel from a couple different stations, put Diesel Kleen in the tank, keep it full and under a shed and this still keeps occuring. Now they want me to replace the entire fuel system at nearly $2,000. Has this happened to anyone? I am beyond frustrated with this tractor and the alleged fuel problems.