small engine problem
 

in my 88 gxl the engine will rev up then down a few 100 rpm around 1250 rmp and around 1900 rpm some one told me it might have been an air filter i replaced that last night and it made a little diffrence but it did not solve the problem Im not sure what it is so any information would be very helpfull
Justin

Could be tps or bac or a number of things.