How to Fix a Yamaha 9.9HP 4 Stroke Outboard – EP1 Compression Test on a Non Runner

In this episode, I begin the journey of fixing a Yamaha 9.9HP 4-stroke outboard engine that hasn't run in years. If you're dealing with a non-runner or just want to know how to assess an outboard's health before buying or repairing, this is the place to start. In Episode 1, I show you how to perform a compression test — a vital step when troubleshooting any outboard engine. You'll see what tools I use, how I test each cylinder, and what the results mean for the rest of the rebuild. Compression testing kit SHOP NOW LINK: https://amzn.to/4ks5voc Fogging Oil: https://amzn.to/45AvQf4 SHOP NOW 9.9hp to 15hp carb upgrade: https://amzn.to/448v8EE 🛠️ This video is ideal for: DIY outboard repairs Yamaha 4-stroke owners Used outboard engine buyers Boaters looking to save money on servicing 💬 Drop a comment if you’ve got questions about your Yamaha outboard, or let me know what you want to see in Episode 2! 🔧 Subscribe for more real-world outboard repair tips and boat DIY content. #YamahaOutboard #OutboardRepair #99HP #CompressionTest #NonRunnerFix #BoatDIY