This may mean there is a clogged air filter. When the air filter is clogged air is pulled past the piston rings causing the mower to smoke. In order to stop the smoke replace the air filter and check the pistons. However, if the mower continues to smoke after replacing the air filter and checking the pistons, it is probably time to bring it into a repair shop.
If your mower won’t start there may be a faulty starter, bad spark plug or a clogged carburetor. In order to fix this you must use an ohmmeter to test starter and spark plug. If the starter and plugs are bad then replace them. Still won’t start? Check the carburetor. If you left old fuel in the engine it evaporated causing clogs. Clean it out and try to start it again.
If your mower is overheating you may have clogged cooling fins, which is part of the engine’s cylinder head. To stop the overheating clean out the dead grass, leaves, etc.
If your riding mower rides bumpy, it is probably due to lack of oil. To avoid expensive repairs make sure to check your oil regularly, but if you are noticing a bumpy ride check the oil immediately.
Out of Oil
If you have forgotten to check your oil in a while and you let your riding mower run out then you need to bring it into a repair shop. You most likely will need a new engine, especially if your mower is an older model.
If you are experiencing engine trouble it might be time to come into the repair shop and get a new engine. Although new engines can be expensive it is often still cheaper than buying an entirely new mower. If you have a newer, high quality model, getting a new engine will lead to many more years of use. However, if you have an older, lower quality model it may make more sense to replace your mower.