Ey up. Anyone get any good ideas how to clean carbon off valves? im rebuilding some heads and the valves have 25 years worth of carbon on them. I’ve read a few things like oven cleaner but I don’t like the idea of anything harsh on them. If the answer is elbow grease then so be it but just wondering if there are any tips
I always came back to a good quality rotary wire brush attachment on a bench grinder myself. A lot of the brushes are five-minute wonders though unfortunately, and need to find a good source myself these days.
I recently cleaned the valves out of my old Mulitstrada engine and just stuck the stem of the valve in an 18v battery drill, started with a Stanley knife blade to scrape the worst off and then went to wire wool and valve lapping paste. Andy
Always count on you two to give some ideas, thanks chaps I tried a wire wool on a Dremel but it just didn’t cut the mustard., just cheap crap as you eluded to @Chris I’ve got some razors knocking around. I’ll go in the hunt for a decent bit of wire for the bench grinder.
agree, I can't even think of a second best to a rotary brush, and on the really stubborn stuff you even have to reverse the brush to remove it all. I probably don't need to add, be very careful, you sometimes have to go in hard but confident, and make sure you've got nothing nearby that could get caught up and wound around the rotating brush. It used to be easy to get these, you just went to a "trade" outlet but the term trade has almost melted into DIY/China nowadays.
You can get them really clean (like new) with nail polish remover or any commercial solvent based on Ethyl Acetate, it works as a carbon solvent and does not attack the metal in any way. For heavy deposits soak them overnight. Sometimes it just has to be scraped off
went for the scrape in the end, and about 30 soft wire wool bits on a dremel. came up pretty well but it was a bit of a ball ache
Mount the valve stem in a drill, spin it up and take sand paper then wire wool to the face as it's spinning, making sure not to contact the valve seating face.
Anything that falls off after a night of soaking with a non-hazardous chemical would get whipped off with ease on an industrial rotary wire brush but if you don't have one then I totally respect any method that works eventually. The sort of hard thick crust deposits that I used to see on exhaust valves, i've yet to see on a motorcycle valve myself anyway.
