the car runs fine, but after 20 miles it starts loosing power, dosent fell like a fuel cut problem. the lights dim and all the lights in the cluster turn on then the engine dies? any ideas? or previouse experiences?

Well to my experience I would take the car to auto zone,or advance auto and get your charging system checked.It could be your battery is not holding a proper charge(old age,cracked plates inside batt,dead cell) or alternator is going or alter belt is loose.Unless your battery terminals are loose or have a bad ground,or even a loose positive cable at alternator maybe.I am going soley on some basic items unless there is something on your gen that I am not fluent with.Def check with a multimeter if u have one but the stores can better check bc it loads the system and verifies if said items are good or bad,unless some minor electrical flaw like I stated.How old is the battery and is the alternator orig,or not just consider the basic items first,bc it could be something SO simple.

Ya it sounds like a charging system problem.