Jello in your FPV feed from motor mounting issues shows up as wavy horizontal lines that make your video look like it's underwater. The first step is diagnosing where the vibration originates. Power off your quad and physically check each motor by hand. Grab the bell and try wiggling it side to side. Any play beyond the normal bearing movement indicates a problem. Next, check every motor mounting screw with a hex driver. I've seen screws that look tight but are actually half a turn loose, and that tiny gap creates massive vibrations.
Remove each motor one at a time and inspect the mounting surface on both the motor and frame. Look for cracks in the carbon fiber around screw holes, which happen after crashes. A cracked arm flexes during flight and turns your motor into a vibration generator. The motor bell should spin freely without any grinding or catching. Bent shafts are common after prop strikes and create an off-center rotation that no amount of tuning can fix. Hold the motor up to a light and spin the bell slowly while watching the gap between the bell and stator. It should stay consistent all the way around.
When remounting motors, clean both surfaces thoroughly. Carbon dust or dirt prevents flush contact. Apply medium-strength threadlocker like Loctite 243 to each screw and tighten in a cross pattern, not sequentially around the circle. Torque them firmly but don't strip the threads. Some builders over-tighten to two or three newton-meters when 0.8 to 1.2 is plenty for M3 screws in carbon.
If your frame uses standoffs between the motor and arm, verify they're all the same height and not damaged. Mismatched standoffs cause the motor to sit at an angle. On frames without standoffs, sometimes adding thin rubber O-rings between the motor and carbon helps isolate vibrations, though this is controversial because it can reduce cooling. I only recommend it as a last resort.
After reassembly, do a no-props power test. Slowly increase throttle while holding the quad and feel for excessive vibration. The quad should feel relatively smooth at cruising throttle. If vibration persists after confirming tight mounting, your problem might be unbalanced props, damaged bearings inside the motor, or a bent shaft that needs motor replacement. I've traced jello to a single motor with worn bearings countless times. Swap motors between arms to isolate which one is the culprit if visual inspection doesn't reveal the problem.
