Toro Lawn Mower Engine Surging

The sound resembles repeatedly throttling up and powering down the mower.

Toro lawn mower engine surging.

Sounds like the governor linkage may be stuck broken linkage spring. The owners manual said to replace the air filter and spark plug at 100 hours. Lawn mower surging results from continual accelerating and decelerating of engine revolutions. So what causes lawn mower engine surging.

Empty the gas tank properly. The warmer the engine is the worse it gets. Starting doing this when i had about 100 hours on the meter this past july. The number one cause of mower engine surge is using gasoline that is old or contaminated perhaps by water condensation usually as a result of leaving gas in the mower over the winter.

I can manually put the choke on with my finger and it will smooth right out. My 2019 toro ss3225 with the toro built single cylinder engine. Runs rough so could it use a tune up. Five problems that cause lawn mower surging.

Dirty faulty carburetor. Replace the fuel in the tank and the fuel filter. Look for dirt debri around the governor linkage and wash brush blow any debri from linkage and ensure linkage mechanism is. Sometimes ethanol in gasoline can cause damage to the carb and it creates surging.

If you do all that and it s still surging i would replace the carburetor with the proper oem replacement carb. Surging is also caused by water that got into the fuel. It now has 159 2 hrs. The most common reason for a surging lawn mower engine is a blockage in the fuel supply but there are other possibilities.

Many homeowners forget or choose not to drain the gas from their mower s tank at the end of each season. Toro lawn mower. The mower may not die completely as this happens but it may surge the entire time you mow the lawn. Check and clean the vent.

A mower left in a heavy rain or condensation on a hot summer day can choke the engine. Knowing that an improper balance of fuel and air causes surging helps develop your troubleshooting plan. This toro lawnmower with a briggs and stratton engine starts and runs but only at half speed. There s nothing to worry about that.

Tjcox6841 tom you did not state your engine or model so i will post some what generic answer. Although it may mow your lawn competently the whole time you ll probably be thinking why does my lawn mower sound like it is surging it won t be such an enjoyable mowing session will it. Starting surging when it idles. However if it keeps surging while you re using it like going up and down or even dies then you have every reason to be concerned.