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How Do I Fix Kohler Engine Surging?

Surging on small engines such as a Kohler engine can cause by a lean condition, as any leanness is likely caused by an exposed vacuum leak. These machines’ RPMs can go surge up and down, and at full throttle, or pop through the muffler. And, if the fuel supply is clean as well as good flow it comes down to carb service. 

Now, how do I fix Kohler engine surging then? Try cleaning the old carb or replacing the carburetor to resolve a Kohler engine surging. You should also troubleshoot and check the electrical circuits, or the jet.

Reasons behind the surging

How Do I Fix Kohler Engine Surging

Investigating the root of the problem is the first thing to do before looking for a fix for surging issues. Some of the reasons might be:

1. Lean condition (which is the occurrence of leanness is a new carb owing to vacuum leakage) 

2. Insufficient amount of fuel consumption

3. Fuel levels

4. Using lower-grade fuel on the engine

5. Inputting inappropriate type of fuel on an engine specifically designed to perform on another. 

6. Contamination of water with fuel due to heavy rainfall. 

7. Stored below optimum temperature

8. Faulty plug or cable.

9. Governor faults.

10.  Worn out or periodically skipping gears. 

How Do I Fix Kohler Engine Surging?

A healthy engine will provide you with more power out of the engine. There are several methods to follow to stop your Kohler Engine from surging. Try following steps.

Kohler Carburetor Troubleshooting

  • For the carburetors having the Plastic Slow Idle Speed Jet, the solution is quite simple, that is, remove the plastic jet, and use a drill bit to bore the hole out to a larger diameter.
  • Maintain the saying: “Start low and go slow”- which expresses don’t pick a large drill bit and bore your jet to too big of a hole. If you overdo it, you’ll waste too much fuel. Keep in mind, you can always go larger but you can’t go smaller without buying another plastic jet. 
  • There are black and red jets. Although the black jets are smaller than the red ones, the red ones still aren’t big enough.
  • On the contrary, the carburetors having non-adjustable jets won’t work the same. In this case, a low idle adjustment needle comes to the rescue. An initial check-up of the fuel line, the fuel filter, and the air filter can give you an idea if they’re clogged or not. If yes, then clean them with a careful hand. 
  • If not, then the problem might be lying in the jets. There’s a needle right underneath the fuel cap to monitor the fuel flow. Turn the cap counterclockwise a little bit and run the engine again to see the difference in the noise. Continue to turn the cap with a screwdriver until the sound becomes better.
Kohler Carburetor Troubleshooting

Examining Electrical Circuits of Engine

Check the connection from the battery to the ignition switch to see if contact is present. Once secured, follow the circuit through the safety switches to the starter solenoid to troubleshoot the readings of both voltage and continuity.

With the aid of proper reference material at hand, you can easily evaluate if the electric circuit is in good shape or not. So, in this regard, you need a volt-ohm meter to check the flow.

Examining Electrical Circuits of Engine

Replacement of Carburetor

If cleaning the old carb doesn’t create any impact (as there’s water, soil or any other contaminants might be present), then buying a new one will be a feasible solution.

Replacement of Carburetor

Make Governor Adjustments

Try making made adjustments to the governor as instructed in the Kohler service manual, and change the spring setting, if the governor is the issue.

Precautions to Avoid Surging

You can easily keep your Kohler engine in a sound shape if you consider maintaining a few things. Such as, refrain from using fuels that are not suitable for your engine. Store your machine at an optimum temperature to increase its vital. 

Also, check your carburetor regularly and release if any amount of extra air pressure is observed inside. As a result, the engine will dodge lean conditions pretty smoothly. Look for cables and plugs to ensure a proper connection before starting the engine.

Adjustment of the Carburetor on Kohler Engine

  • First, start the engine to keep it for 5 minutes on standby mode to reach the operating level temperature. Note that plain ground is necessary to initiate the task. 
  • Move the throttle to the “Slow” position. 
  • After that, start the tachometer with a four-cycle engine. Set the carburetor on the right part of the Kohler engine directly under the air filter. 
  • There’s a black limiter cap situated at the top of the idle screw. Take a flathead screwdriver and rotate the limiter cap, until the tachometer displays 1650 plus or minus 75 rpm. 
  • Twirl the limiter cap clockwise to decrease the rpm and counterclockwise to level up the rpm.


1. Can spark plugs cause surging?

Ans: Dirty or worn-out plug can cause vehicles surging which ends up in jerking acceleration ultimately. Sparking plugs might not create ignition to the fuel in your engine to initiate a good speed. As a result, bumpy motion occurs. 

2. Can a bad fuel filter cause surging?

Ans: Yes, by decreasing air pressure clogged fuel filters. Fuel filter requires being clean to have enough flow of fuel spontaneously.

3. How do I know if my carburetor is too rich or lean?

Ans: Poor fuel economy, slow acceleration, the intense smell of gasoline at standby condition, uneven pace (will often slow from regular idle RPMs and then stop), cold starts don’t demand choke, black spark plugs or black muffler end pipes- these are the common signs to look for. 

4. Why does my Kohler engine keep shutting off?

Ans: It’s probably because the carburetor might be jammed from leaving traces of gasoline every now and then. Clean it cautiously to see the improvement.

To Conclude

Kohler engine is a multifunctional appliance and systematic use is needed to keep surging at arm’s length. Moreover, constant monitoring of carburetor, fuel movement, pressure, and electrical wires will save you from the hassle of repairing your machine. However, if your Kohler engine still has surging issues, you can try out the steps described above or seek professional help.

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