I'm used the tractor in Low range. Thanks for telling me about the pedal. I'll try your suggestion although I've never had that problem since I've had the tractor.
The tractor is about 10 years old. I put winterized diesel fuel in it in November. I don't think the fuel tank was ever cleaned. I use the tractor only about 6-12 times a year on average.
Once I begin asking it to work, like using the blade for snow or pushing with the bucket the RPMs will drop and stall or almost stall. May work fine for 10 or 15 minutes before it quits. Fuel filter has been changed and air filter cleaned. Help.