Common Problems With Kohler Engines (According To Owners)

Kohler is an American company with a rich history, going all the way back to 1873. Founded in Wisconsin, it got its start with farming equipment and bathroom accessories before starting a division for industrial engines, offering the first automatic residential backup generator in 1920. Throughout the decades, Kohler has been a reliable presence across the American landscape. But it seems things have changed.

Kohler used to be a respectable marque with solid engines that could take punishment. For many of its products, it seems Kohler is now cutting corners, targeting the budget end of the market with cheap consumable products using flimsy components made by the lowest bidder. In 2007, Kohler began a joint venture in China to build small gasoline engines in Asia instead of the United States. The once great American marque is now a generic multinational corporation, with parts and design outsourced to countries with cheap labor.

For the uninitiated, Kohler engines are fitted to a large variety of products from different brands, such as lawnmowers from Cub Cadet, Toro, and John Deere, as well as generators, wood chippers, water pumps, and more. For combustion engine devices, the most attention online is given to lawnmowers, so we'll start there and then cover other products with Kohler engines. Note that in September 2024, Kohler Engines and Kohler Energy officially rebranded to Rehlko (an anagram of Kohler) after being acquired by global investment firm, Platinum Equity. For the sake of simplicity, we will continue to refer Rehlko as Kohler throughout the article.

During our research, we found that older products such as the Magnum and the Command are still well regarded. However, the overall opinion was pretty low for Kohler engines, with most mechanics recommending Kawasaki engines instead, which are simple and bullet-proof, or Honda for those with deeper pockets.

Common complaints were leaking valve covers, loud vibration issues, and very cheap and nasty air filters that offer little protection, such as on the RH Series 6.5 hp.  Oil leaks were extremely common, as we found many reports of oil running out suddenly on Courage engines — which can lead to catastrophic engine failure – even if it has only had a very short operating life.

When we surveyed Lowe's owner reviews of the Husqvarna YTH21K46 ride-on lawn mower, multiple owners reported loose fittings and gasoline suddenly dumping on the ground on brand-new purchases. In 2011, there was a recall of Husqvarna, Cub Cadet, and Troy-Bilt lawn mowers and lawn tractors using Kohler Courage twin-cylinder engines. A wire connector could become disconnected, causing a switch failure. This would result in the mower blades not shutting down, thereby "posing a laceration hazard." If you're looking for something more trustworthy, see our list of the most reliable lawn mower brands.

Looking through internet forums, special criticism is aimed at Kohler's single-cylinder Courage engines. Courage engines have plastic cam and governor gears which break easily. Blown head gaskets were a very common complaint, as were reports of knocking. Even more serious, cracked engine blocks were common — there are multiple videos on YouTube with backyard hacks to bodge-fix the problem. One especially notable complaint was that Kohler has been using instant-gasket sealer instead of proper gaskets, leading (rather predictably) to oil leaks. This has all been exacerbated by widespread complaints of poor customer support from dealers.

Seven gasoline engines were recalled in 2018 due to a faulty fuel cap. These engines are used in a large selection of outdoor equipment, such as generators, water pumps, and log splitters. This could over-pressurize the tank, leading to fuel leaks and a potential fire hazard. As for Kohler's generators, the overall picture for generators seems to be good — Kohler products even topped the list of some consumer tests — but not its customer service. Overall, the advice from Kohler owners is clear: either buy something old and sturdy — and actually made in America — or buy something Japanese.