Fixing a smoking lawn mower is usually not all that hard or complicated. Often times it’s something pretty simple like over filling the oil. But whatever the reason your lawn mower is smoking, I’ll give you some ideas on what is exactly wrong and then show you how to fix the issue.
Smoke is a common and a sure sign that something in the engine isn’t working properly. Yes, it may look very bad seeing your motor smoke, but it really isn’t a very serious issue most of the time.
But if you ignore the signs and leave the engine untreated, it will definitely become a big issue that will end up costing you money on repairs.
There are different types of smoke and this article is written to help you recognize and control the issues at hand.
Black Smoke
This type or color of smoke usually caused by with the mower’s fuel system or carburetor. One of the most common causes is that there is an unequal balance of fuel and air in the lawn mower’s system.
Too much gasoline isn’t a problem for most people but it actually floods the engine in this case.
Some probable causes can be from a dirty carburetor that needs some cleaning and tuning or the air filter is too clogged up. The first and easiest thing to do is by checking the air filter. A high percentage of this very issues is generally from dirty air filters.
All you have to do is remove the mower’s air filter and clean. Some people do this by using their mouths and blowing or if you have an air compressor, use it for a more thorough cleaning.
If your air filter is clogged then the best thing to do is to remove and replace it with a new one. Clogged air filters are extremely hard to fully clean so replacing it is the way to go.
After doing this action try starting the engine to see if the problem is fixed. If your mower’s engine is still producing black smoke then you need to adjust the carburetor.
This step will produce a more balanced air-to-fuel mixture. This really isn’t too hard and can be done done twisting a screw.
Depending on you make and model, you should take a look at your owners manual for complete information, but if this doesn’t work you definitely should have it professionally repaired.
White or Blue-White Smoke
Unlike black smoke that is caused by the unbalanced burning of more fuel to air; white smoke signifies the burning of excess oil. Yes, having too much oil is a bad thing as with too much gas. Many times with this issue is that you can start the engine and just let the mower run for a while. This is effective for burning off too much oil.
Leaked oil can be a result of the mower being turned over or tilted to one side causing it to leak fluids. Every engine has it’s own tolerances, but don’t turn the engine off because this action further delays the issue.
Over filling the oil reservoir will result in your mower’s engine producing white smoke so just closely monitor the amount of oil or fuel you put into the engine. If this isn’t the case and the smoking persists, you can have a more in-depth issue with the crankcase. Check the crankcase for any leaks and if there is too much air in the crankcase, the mower’s breather won’t be able to handle it.
Unfortunately if you can’t detect any air leaks; the best thing to do is take your mower in for professional service. In addition to these issues any worn out rings or cylinders, blown head gaskets, or an ineffective breather will produce white smoke. These issues require a skilled mechanic for service.
Smoke is usually a precursor to an issue and not necessarily the issue itself. Always closely monitor the amounts of gas and oil fluids put into the engine and try to keep the mower sitting on a balanced level ground.