Unlock the Right Part
for Your Repair
Find the exact part you need
Enter your model number to see parts that fit your machine.
Price Match Guarantee
In-stock parts ship the same day
365-Day Return Policy
Price Match GuaranteeChoose Product
Identify Problem
03
Find Solutions
HomeRepair HelpExmark Mower RepairExmark Lawn mower runs rough Repair
Exmark Lawn mower runs rough
If your Exmark lawn mower runs rough, sputters, or the engine runs unevenly, the carburetor is the first place to look. On these mowers, stale fuel often leaves behind a sticky residue that clogs the carburetor and causes mower engine surging, rough running, or poor throttle response. Start by cleaning the carburetor with carburetor cleaner. If that does not fix the problem, a carburetor repair kit may help, or you may need to replace the carburetor altogether. Next, check the spark plug for cracks, electrode damage, or heavy carbon buildup, and use a spark plug tester to confirm it is producing a strong spark while the engine is cranking. A weak or failed plug can make an Exmark lawn mower run rough after starting. If the mower is still sputtering, inspect the fuel filter, since old fuel can clog it and restrict fuel flow enough to make the engine stumble. Draining old gas and replacing the filter is often the fix. Enter your model number on RepairClinic.com to find the exact Exmark carburetor, spark plug, fuel filter, or other replacement part that fits your mower.
01 - Exmark Lawn Mower Carburetor
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the lawn mower for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and cause the engine to run roughly. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
Enter model number to search for the required part specific to your product
Top Solution
02 - Exmark Lawn Mower Carburetor Repair Kit
The carburetor might be clogged. A clogged carburetor is most commonly caused by leaving fuel in the lawn mower for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and cause the engine to run roughly. If the carburetor is clogged, try cleaning it with carburetor cleaner. If cleaning the carburetor isn’t effective, rebuild or replace the entire carburetor.
Top Solution
03 - Exmark Lawn Mower Spark Plug
Inspect the spark plug for signs of wear or damage. If the porcelain insulator is cracked, an electrode is burned away or damaged, or there is heavy carbon buildup at the electrode, replace the spark plug. To determine if the spark plug is defective, use a spark plug tester. You should see a strong spark between the tester’s terminals when the engine is cranking. If there is no spark, this indicates that the spark plug is defective and should be replaced.
Highly Likely
04 - Exmark Lawn Mower Fuel Filter
The fuel filter might be clogged. A clogged fuel filter is most commonly caused by leaving old fuel in the lawn mower. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the fuel filter and cause the engine to run roughly. If old fuel was left in the lawn mower, drain the old fuel from the fuel tank and replace the fuel filter.
Less Common
Frequently Asked Questions
Why does my Exmark lawn mower run rough after starting?
Can a bad spark plug make an Exmark lawn mower sputter or run unevenly?
How do I know if the carburetor on my Exmark mower is clogged?
What should I check first if my Exmark lawn mower runs rough with old gas in it?
How do I find the right carburetor, spark plug, or fuel filter for my Exmark lawn mower?
Shop by Exmark Lawn Mower Parts
Shop by Popular Exmark Lawn Mower Models
Our Story
Family-owned and operated since 1912, Burke America Parts Group is the longest-running genuine appliance, HVAC, and outdoor power equipment parts solution in North America. At Repair Clinic, we're proud to be an international brand trusted by the pros as well as the DIY community.
About Repair Clinic
© 2026 RepairClinic.com