These days, most ride on mowers will come fully equipped with a muffler on the exhaust port. This is supposed to force the exhaust to travel through some noise-cancelling chambers inside the muffler before it is released into the air. It also provides the engine with backpressure, which allows it to run at its maximum horsepower.
Because of all the pressure being placed on the muffler, over time it is known to crack or sustain damage to the gasket seal. This will cause the mower to run much louder, which can be a nuisance to your neighbours when you try to cut your grass early on a Sunday morning. If you think your ride on mower is experiencing a similar problem, you can fix it.
If you have just used your mower, you will need to leave it to cool down for a few hours before working on it, as the engine is known to get quite hot. Locate where the muffler and exhaust pipe run from the front of the engine, then use a wrench to unscrew the bolts holding the exhaust pipe to the exhaust port. You can then pull the pipe off and out of the muffler.
Give the muffler a thorough look over to ensure that it hasn’t developed any cracks or rust (due to condensation). If it has, use the wrench to remove the mounting bolts and replace the damaged muffler with a new one.
If the muffler appears fine, take the old gasket off the exhaust port and scrape off any dirt using a fingernail. Place a new gasket over the port, slide the exhaust pipe back into the muffle and tighten the whole thing up. Give your ride on mower a start and see whether this has fixed your noisy problem.