7 Common 27 HP Kohler Engine Problems Troubleshooting

The common 27 HP Kohler Engine Problems most users notice are overheating, starting failure and rough running. The engine can often cause intermittent issues and stalling. Besides, oil leakage and excessive vibration are commonly seen. 

If you have similar issues with the engine, please move forward. The quick fixes for the above issues are:

1. Cooling down the engine in recommended ways.
2. Replacing the damaged spark plug.
3. Removing dirt and particles from the air filter.
4. Replacing faulty spark plug or ignition coil.
5. Cleaning the dirty carburetor and fuel filter.
6. Tightening the loose fittings or changing the damaged seals.
7. Changing the loose or broken belt.

We have also discussed each issue in-depth below. Check them out to fix your mower’s 27 HP Kohler engine at home. 

Read: 25 HP Kohler Command Pro Engine Problems [With 4 Easy Fix]

27 HP Kohler Engine Problems Troubleshooting guide

Check out the list of most common issues with the engine, their symptoms and solutions.

	Problems	Symptoms	Instant solutions
01.	Overheating	Smoke, hot surface, shutting down and power loss.	Take frequent breaks, add sufficient oil and coolant, remove dirt from the air filter and fins, and replace a damaged cooling fan.
02.	The engine won’t start	It cranks but does not start, and it backfires.	Use fresh fuel, change the faulty spark plug and ignition components, prime the engine and clean the air filter.
03.	Engine runs roughly	Excessive fuel consumption, slow speed, and backfire.	Use dirt-free fuel, clean the spark plug and carburetor and change the clogged air filter.
04.	Engine intermittent	Misfiring, backfiring, difficult to start, lack of power.	Rewire electrical connections, clean the engine, use fresh and clean oil, and take a break during mowing.
05.	Engine stalling	A sudden shutting down.	Clean the fuel line and filter, clean the air filter, and avoid overheating the engine.
06.	Oil leakage	Oil drops on the ground, low fuel level, oil smell.	Replace damaged gaskets, secure loose nuts and bolts and change the oil pan if it is cracked.
07.	Excessive vibration and noise	Too much shaking and noise.	Replace damaged bearings and tighten loose components.

In the following sections, we will discuss the mentioned issues in depth, including their quick fixing steps. 

1. Overheating

The Kohler 27 HP engine usually becomes overheated due to overworking and low oil levels. It also can be too hot if its cooling fan is damaged or the cooling fins are clogged. 

If the overheating issue goes on, it can damage the engine permanently or make its lifespan shorter. Overheating the engine is also relevant to fire hazards. It can cause engine failure as well when you may need a complete engine replacement. 

How To Fix?

• Avoid over-using and take breaks: Monitor the time when the engine reaches the overheating stage. After that, pause your mowing before exceeding the timeframe. 
• Add the recommended oil level: First, check the oil level. If it seems low, add an accurate oil level, as recommended by the manufacturer. 
• Check the coolant level: Check whether the reservoir has adequate coolant. If the coolant level is low, mix coolant and water following the manufacturer’s instructions and fill the reservoir with the mixture. 
• Replace the cooling fan if damaged: Check the cooling fan of the engine. If it becomes faulty, try to repair it first. When its defect is unrepairable, replace it with a new cooling fan. 
• Clean the air filter and fins: If you notice them dirty, clean them immediately to prevent overheating. Use a brush or compress air to clean them. 

Caution: Do not touch the hot engine while inspecting it. You must use safety gloves for such activity. Moreover, disconnect the spark plug wire before fixing any engine issue. 

2. The engine won’t start

The engine can fail to start because of insufficient fuel, a defective spark plug and ignition problems. It may also happen if the air filter is clogged or the engine has a mechanical issue, like a broken piston valve. 

When the engine does not start, you cannot operate the mower. If you force the engine to start, it can seriously damage the mower. Such a practice is also dangerous for the user if the engine starts suddenly. 

Read: Kohler Engine Identification Missing – [Serial Number Lookup Guide]

How To Fix?

• Use sufficient fresher fuel: If the fuel level is low, add more fuel. You must use fresh fuel as old ones may lack flammable content, another reason for the issue.
• Check the spark plug and ignition system: Replace the spark plug if it is broken or damaged. If the replacement does not work, it can be an ignition problem. Find whether the ignition coils and kill switches are defective and replace them. 
• Clean the air filter: Use a brush to remove dirt from the filter. If the air filter is badly clogged, you must change it.
• Prime the engine: If the engine does not start due to cold weather, priming can be an effective solution. Run some fuel into the engine’s cylinder so it can start again.

Caution: If you have no idea how to handle an engine, go to a professional to avoid further engine damage. 

3. The engine runs roughly

Kohler’s 27 HP mower engine can run roughly if the spark plug becomes faulty or the engine has an ignition issue. Bad fuel with particles also causes the problem. Moreover, mechanical issues, like worn piston rings, can run the engine roughly. 

An engine with the problem consumes more fuel. Besides, it increases the risk of wear and tear and reduces the overall performance of the mower. 

How To Fix?

• Clean the spark plug: Check the spark plug and remove dirt from its surface. Replace it if the component is completely damaged.
• Check fuel filter: Inspect the filter and replace it if clogged terribly with particles. Also, use fresh fuel that is free from debris.
• Remove dirt from the carburetor: Clean the carburetor if it is clogged with dirt. Use commercial carburetor cleaner for the maximum result. 
• Replace or clean the air filter: If the filter is seriously clogged, change it immediately. You can also clean the filter if the dirt is removable.

4. Engine intermittent issue

Your mower engine can have intermittent issues because of poor electrical connection, faulty ignition system and clogging in different components. Besides, overheating is a common reason for it.

Due to intermittent issues, you can experience poor performance and a lack of sufficient mowing power. The engine can also produce harmful emissions.

How To Fix?

• Keep a record of the problem’s time and pattern: Notice whether the issue frequently occurs during hot or cold weather. Also, see if it is relevant to any specific situation like overworking.
• Check electrical connection and components: Reconnect loose wires and poor electrical connections. Change damaged electric components if you find any. 
• Clean the engine: Ensure that the engine is free of dirt and debris build-up. Clean all of the engine’s removable tubes carefully.
• Replace the oil filter and use fresh fuel: If the oil filter is clogged, replace or clean it immediately. Use fresh and clean fuel free from debris. 
• Take breaks: Before the engine gets overheated, pause your mowing. The practice is crucial to avoid overheating and intermittent issues.

5. Engine stalling

Sudden engine shutting down or stalling can happen because of restricted fuel supply, problems in the ignition system and airflow blockage.

The engine stalling issue seriously hampers the user’s productivity. It is also very annoying as the engine stops working suddenly.

How To Fix?

• Keep fuel supply consistent: Ensure that the fuel line and filter are clean. Also, make sure the carburetor has no debris inside.
• Clean the air filter: If the air filter is covered with dust and debris, clean it so no blockage occurs in the airflow.
• Check the ignition system: Ensure the spark plug is clean and has proper gapping. Also, confirm the ignition coil has no crack. 
• Avoid overheating the engine: Use your mower following the recommended guidelines. Be careful about overusing the engine.

6. Oil leakage:

The Kohler 27 HP engine can have an oil leakage issue due to worn gaskets and seals, cracked oil pan, overfilling and loose nuts. 

Oil leakage from the mower engine is bad for the environment. It also has a high risk of fire hazard. If not repaired, it can damage the engine seriously.

How To Fix?

• Replace damaged gaskets: Whenever you notice a worn seal, change it immediately.
• Tighten loose bolts and nuts: Find if any of them are loose. Secure them instantly. If any nut or bolt is lost, purchase the same one and attach it.
• Replace the cracked oil pan: If the engine’s oil pan is cracked, you have no other option except to change it.

Caution: Avoid over-tightening any nut and bolt. Keep any type of flame away while working on the oil leakage. 

7. Excessive vibration and noise

The engine can generate excessive vibration and noise if the bearing is damaged or any internal component is loose. Moreover, the vibration occurs when the crankshaft becomes bent accidentally.

When the problem occurs, you may experience too much shaking during mowing. It will also cause noise pollution. 

How To Fix?

• Change the damaged bearing: Find out the engine’s damaged bearing and replace it with a new one.
• Tighten loose components: If you notice vibration and noise occurring from loose components, secure them by tightening their nuts and bolts.
• Go to a technician if the crankshaft is bent: They will help you repair or replace the bent crankshaft professionally. 

Maintenance Tips to Avoid 27 HP Kohler Engine Problems

Regular maintenance dramatically reduces failures:

• Change oil and filter on schedule
• Use clean, fresh fuel
• Replace air and fuel filters regularly
• Keep cooling fins and engine shroud clean
• Avoid extended storage with untreated fuel

Most serious issues start as small maintenance problems that were ignored.

When should I go to a technician?

If your mower has a warranty, you must directly contact your nearest dealer. Going for any third-party repair, despite having the warranty, can make your unit ineligible for manufacturer support. 

The engine is a sensitive and expensive component of the mower. You must handle it carefully. If you have good technical knowledge, you can fix the basic engine issues at home. 

But, if you are not familiar with engine structure, do not try the above fixes. Go to a professional who can safely repair the engine.

Watch >> Emark Lazer Z Mower – Kohler carburetor issues – 27hp engine troubleshooting

FAQs – 27 HP Kohler Engine

How long does a 27 HP Kohler engine last?

With proper maintenance, many owners see 2,000–3,500+ hours of reliable use.

Why does my 27 HP Kohler engine lose power?

Power loss is usually caused by restricted airflow, dirty fuel delivery components, or carburetor issues.

Is it normal for a Kohler engine to smoke?

Light smoke on startup can be normal. Constant blue or black smoke is not and should be addressed.

Can a 27 HP Kohler engine be repaired?

Yes. Most problems are serviceable without replacing the engine, especially when caught early.