New Member and Recent VF750F Purchase

Hello,

I recently purchased a 1984 VF750F with 16K miles. Overall in pretty nice shape. I recently had new Bridgestone BT045's installed along with a new chain. Next I need to clean out the gas tank. Although the bike runs, the fuel system appears to be struggling at times. The tank's insides are suffering from a failing older attempt to Seal the tank. Although there seems to be alot of chemical cleaners to use, I want to preserve the integrity of the paint which is original and still in great condition. Does anyone know of a process that will not damage the paint? Thanks!