Metal Rescue Tank. Should I Swap to Manual Petcock?

I have a 1980 XS650 Special. I'm in the process of cleaning out the tank with Metal Rescue (concentrate). Used three bottles for 3 gallons. It's sitting in the tank now. I'll also take apart and clean the carbs (it was recently fully rebuilt) and add new fuel line plus inline fuel filter.

I haven't experienced any gas leaks in the vacuum petcock, but I have possibly a vacuum leak somewhere as it backfires and occasionally pops the vacuum hose off (no clamp). I figured I would keep the vacuum petcock as long as it keeps working. I know there are a lot of vacuum vs. manual threads. Even I have been on the fence...

Is there something I need to do for the current petcock while I clean the tank? Do I need to take it apart and clean it? Is there a recommended rebuild/cleaning kit for these?

i wouldn't take it apart to improve it, if it's working. it's finicky. for the record, you can transform it into sort of a manual with little effort. remove the plastic wafer and both diaphragms. put the two halves back together using gasket paper, i used seal-all there too. put lawnmower on/off downstream from it. reserve and prime are now both reserve, and run is still run. the benefit is it won't start spewing gas 1000 mi from home.

also -- those screws that hold the chromed plate screw into the petcock metal, which is weak. you can get longer screws the same size and put nuts on the backside. actually on mine at least the stock screws were so short they didn't even use much of the threads in the petcock

Thanks!

If they work...keep them, they are nice to have, but they will likely fail eventually. I've spent hours rebuilding mine...and have been successful-- for another 6 months or so, but then they ended up leaking again. Rebuild kits aren't that great from what I remember. I ultimately decided to go manual and haven't looked back. You can make them manual, as been stated...but I went with Mikes. They work well, and I only use one side (dual petcocks on my '79)...I just don't "turn on" the other side...although it's all connected.

All hooked up again. I didn't do anything to the petcock (kept the vacuum type). No leaks and working as it should.


Here's a before after in case you are curious.

Using metal rescue on a 75b tank for the first time.Always have done it the old way.Muratic acid for the the bad or a draino crystal and water mix and don’t forget its in there, or vinegar solutions.I’m told by an older m/c garu/friend the metal rescue is the way to go now.If he’s a believer I am too.The big factor I’m told is the temp.70 or above is best. I can now confirm the tank is 4gal as the specs have always said.Never have filled to the brim and measured.Installing new petcocks,but am curious how the originals will look when removed after this process. I don’t throw away much so they’ll go to a bin.Looking forward to the results.Wife is traveling so the house thermostat and laundry shower is mine for a couple days.