Silencer was replaced with a new one 5 months ago.

I drained the gas tank of an '86 Subaru Brat that has been sitting for years and old,thick,dirty,sludgy gas(?) came out. I removed it from the car and want to clean the inside real good before putting it back on. Wondering if there is a solution of some kind that I can use. Any thoughts? Thanks for any advice or tips.

The puttering or popping or seemed starving for fuel happens when a load is puton engine. Ease up on pedal, then gains power.

I just bought My justy yesterday and its a 88 not 90 and it drives fine except when i start to speed up then the car has really bad steering and swerves all over the rood...I have an idea what it could be but id like to know for sure and it doesnt really idle without dieing