I recently bought this older Kubota push mower (5hp 19" cut). It runs, but only on choke, and the motor revs up and down. (hunts). Replaced the pilot jet, but no improvement. You can still get the oem carbs for these for around $100.00 but I wonder if its worth the expense, especially if it doesn't solve the problem. It runs as I said previously, cuts and bags grass very well. Anyone familiar with these let me know what you think. Thanks.