BCR, are you drinking again? LOL....if you chain IS in fact rubbing on the bottom of the chain guard housing, not only should you clean and lube the chain, but also tighten it to spec or the problem will continue. The squeaking sound may also be bad rear axle or front wheel bearings or possibly the brakes are partially stuck/ dirty/ or hanging up. To check for spark, 1:remove the spark plug(make sure it is good/buy a new one) 2: attach the spark plug wire to the spark plug 3: ground the metal on the side of the spark plug to the engine ( head or cooling fin) 4: with the kill switch in the "on" position, turn the engine over and see if you have a spark (yup, you will need a recoil starter for this step). Like BCR said, you can pull or push start the trike in 2nd or 3rd gear.
Don't worry...just run watcha brung...