Yamaha Lower Unit Assembly - F2.5 - 69M-G5300-00-4D - See Description for Applicable ModelsYamaha Lower Unit Assembly Complete Lower Unit System 69M G5300 00 4D Overview On smaller outboards like this, the lower unit does all the heavy lifting when it comes to putting power into the water. When its in good shape, you get smooth shifting, steady push, and no extra noise or vibration. But once it starts wearing out, even a small engine will feel rough and unpredictable. This is the kind of replacement that brings everything back to a clean,