best material for cleaning heavily rusted parts ?

[fieronut]

Well after some search I finally found a semi decent gas tank to replace my rusted out original on my 82 650 nighthawk. Now I need to transfer over my fuel petcock from the original tank. Unfortunately it's in just as bad shape as the tank, full of rust etc. I'm soaking it in varsol for now. Does anyone have any better idea on how to get all the rust and gunk out of it so hopefully I can salvage it ?. Apparently the petcock like the tank is unique to this year and so of course is not cheap to replace.

[Folsoml]

Welcome here! Should you find yourself in need of a replacement, these bikes all share the same size petcock:

CB1000C A (83)
CB1100F A (83)
CB650 A (82)
CB650SC A (82) (yours)
CB750C A (82)
CB750SC A (82)
CB750SC A (83)
CB900C A (82)

[snowdragon3]

for rust a good solution is Workshop Hero's Metal Rescue (http://www.summitracing.com/parts/app-1 ... oCtxLw_wcB)

I buy mine at home depot, about $25 a pop.

[coffee_brake]

Good old CLR from any big-box store or home improvement store will work great.

CLR is Calcium, Lime and Rust remover. I use mine in an ulstrasonic cleaner, but you can just use a plastic cup too. Maybe set it on the washing machine during the spin cycle.

You would not believe the difficulty I had finding a rebuild kit for my petcock. Take all the rubber bits out of yours and be careful with them.