Getting Your 400ex Valve Adjustment Done Fast

If your quad is starting to sound a bit like a sewing machine or it's becoming a pain to start when it's cold, it's probably time for a 400ex valve adjustment. The Honda 400ex is one of the most reliable machines ever built, but it's an air-cooled engine, and those valves tend to move around a bit as things heat up and wear down over time. It's a standard maintenance task that a lot of riders ignore until the bike starts running poorly, but honestly, it's something you can knock out in your garage on a Saturday morning without much stress. ...

February 12, 2026 · 6 min · Cark Kowkobany