Hello, OurRuritan club has a Gravely Promaster 300 with a Kohler Magnum 20 engine, bought used 3 years ago, date of manufacture unknown, 680 hours on the meter.
Works great, except that when it's first started, the engine will cut off when the brake lever is released, and then reignite if the brake is immediately reapplied, causing the engine to backfire thru the muffler. As the engine warms up, this problem goes away, but then when I hit the go forward pedal, the engine will cut off til the pedal is released. As the mower warms up more, feathering the forward pedal will get it going til the problem disappears for that time of operation.
Lately, the engine has been momentarily cutting off during normal operation.
Any suggestions are greatly appreciated.