​How to tell if Your Kohler K Series Engine Needs a New Piston

How to tell if Your Kohler K Series Engine Needs a New Piston

So your Kohler K Series Engine is burning oil, smoking, or losing compression and you want to look inside to see what it needs.

Do you need a new Kohler K Series Piston? 

How can you tell?

Well in this article I will show you how to determine if your Kohler K Series Engine needs a new piston. This applies to all Kohler K141, K161, K181, K241, K301, K321, and K341 K Series Engines.

You can inspect the condition of your piston without taking your entire engine apart. In order to remove the piston you need to:

• 1.Remove the engine from your equipment
• 2.Mount engine into engine stand if available. (Highly Recommended tool)
• 3.Drain Oil
• 4.Remove Oil Pan
• 5.Remove Connecting Rod Cap Screws
• 6.Gently tap connecting rod out from the underside of the engine. If you have the engine mounted on a stand you can just flip the engine upside down, and tap connecting rod down through the top of the engine. Make sure you have a hand below the engine to receive the piston and connecting rod.

Now that you have the Piston and Connecting Rod out, you are going to measure and visually inspect the condition of your piston.

When inspecting your piston look for score marks or deep scratches on the edge of the piston above the top compression ring. If you have excessive score marks, gouges, or dents, you should replace the piston. If it looks good you will need to measure the piston skirt.

You can measure the piston skirt using a set of calipers or a micrometer. I suggest using a micrometer as it is easier to take an accurate measurement. If you have a round piston like in the photo below you have what Kohler Refers to as a Style A piston. You need to measure the width of the piston right below the bottom ring groove and perpendicular to the wrist pin. 

Compare these measurements to the specifications found in the Kohler K Series Service Manual. The Specifications are listed towards the beginning of the manual.

If your measurements are not within specifications you should replace the piston.

If you have never done so we always recommend replacing the piston rings if your engine is burning oil regardless if you need a new piston or re-use yours.

We will cover how to measure and inspect your Kohler K Series cylinder bore, connecting rod, and Crankshaft Journal in future articles.

Thank you for saving the tractors!