RE: what heli is this??
You should break it down and inspect the bearings. There's things you can do depending on the condition and run time of the motor. For cleaning gunked up metal parts, old green cheap antifreeze in a crockpot on low works wonders but you have to be careful with animals and not to breathe the fumes and not to cook food again, I have a yard sale 5 dollar crock pot that works like a champ.