Removed the gas tank on my CT110 and poured muriatic acid into it after plugging the outlet tubes. I tried sealing the filler opening by placing a part of a plastic glove over it and putting the cap back on. It sort of worked. It only dribbled a little and fortunately the acid didn't hurt the paint. Cleaned the heck out of the inside of that tank though. Looks like new in there. I ran a bit of hose from the hair dryer into the tank and blew some warm air into it for about two hours to dry it out. Now on to the Por15 coating! Hey! One word of warning, I have used acid a few times and never had a problem with it but this time when I set the open, gallon jug of acid down, the impact of the jug hitting the cement floor caused a couple of tiny droplets to shoot up and one of them went into my left eye. I ran as fast as I could to the nearest sink and washed it out. Fortunately, no damage done. I wore my safety glasses after that. Sheesh!

Doug - Olympia - Washington
 I don't know how many CTs I have.