Incomplete installation of the battery, damage from forcing the battery to lock, battery bracket is misaligned Insert the battery completely and then apply lock. Do not apply force on the key, doing so may cause damage Check the bracket for dirt and ...
Loosen all bolts, align all brackets, then tighten little by little. If threads are stripped or holes don’t line up, contact ENVO for hardware or alignment advice.
Check motor mount bolts for tightness. Inspect for any loose or rubbing parts. Confirm vibration isn’t from the chain or rear wheel. Contact ENVO support if noise/vibration persists, as motor may require inspection.