John Deere 425 Bogs Down Under Load? We Found and Fixed The Problem!

This John Deere 425 had a serious power loss problem and would bog down badly under load, making it clear something was wrong. In this video I go through the full diagnostic process step by step to find out why this Kawasaki FD620D V twin engine was running weak and not pulling like it should. I start by checking the fuel quality, then test each cylinder independently to narrow down which side is not contributing. After confirming one cylinder is dead, I check spark on that side and verify ignition is not the problem. From there I remove the valve cover and find the real issue causing the power loss. I show how to replace the bent push rod, how to set the valve lash correctly, and how to get this John Deere 425 running with full power again. After the valve train repair the engine runs much better, but there is still a slight bog under load. I explain why that points toward a carburetor or fuel delivery issue and how a slight choke test helps confirm it. The customer declined further carburetor service, but I go over what the next repair step would be and why. If you have a John Deere 425 that bogs under load, has low power, runs on one cylinder, or seems to have valve train trouble, this video should help you understand how to diagnose it properly before throwing parts at it. Thank you for watching!! If we helped you out and you want to show your support - LIKE, SUBSCRIBE or give us a shout out below If you saw something you didn't like leave your comment below as well, these things help us get better! To see our recommended tools and products visit our Amazon shop at https://www.amazon.com/shop/individualizedrepair Interested in starting your own small engine repair business? Check out my other channel, where I share tips on building a repair company from scratch with minimal investment @SmallEngineEdge1 The links contained here are affiliate links for which we may be compensated if you make a purchase Parts Used: Push Rods 13116-2057 https://amzn.to/4wKq1ai Rocker Cover Gaskets 11061-2182 https://amzn.to/4nuOhZv Video equipment: GoPro Hero 13 https://amzn.to/4m3kZQE GoPro Media Mod https://amzn.to/46R95UK GoPro Light Mod https://amzn.to/44wIGdA GoPro Macro Lens Mod https://amzn.to/4d99lQi Microphone: DJI Mini Mic 3 https://amzn.to/4bmNROT Don’t forget to like, comment, and subscribe for more lawn mower repair tips, troubleshooting guides, and DIY small engine fixes to keep your equipment working smoothly! Save some money by doing it yourself! About Us: My name is Martin. I have been repairing tools and small engines for almost 20 years. We operate a small engine repair shop in Illinois. We service / repair Briggs & Stratton, Kohler, Kawasaki, John Deere, Cub Cadet, Toro Tecumseh, Loncin, Honda, Craftsman, Husqvarna, MTD, Troy Bilt, Simplicity, John Deere, Exmark, LCT, Generac and many more brands. We work on riding mowers, walk behind mowers, snow blowers, zero turns, generators, pressure washers and much more. We normally repair about 4,000 pieces of equipment every year and look at many more that are beyond an affordable repair. Hopefully our videos will save you some money and give you the information you need to work on your own equipment or figure out the issue at hand. Disclaimer: Links included in the description are affiliate links. As an Ebay & Amazon associate we earn from qualifying purchases. There will be no additional charge to you for purchasing here. We appreciate your support, which allows us to continue to provide original content! Please be careful when repairing any piece of equipment and follow all possible safety measures. This video is for entertainment purposes only #johndeere425 #kawasakifd620d #johndeeretractor #smallenginerepair #valveadjustment #smallengine #lawntractorrepair #smallenginediagnostic