Ken, The active ingredient in modern carb cleaners is xylol, a strong petro-chemical solvent. Although it will not damage metals it may leech the binding agents in old paper or cork gaskets. if the carb is dissasembled and gaskets removed you are OK. I also sometimes use denatured alcohol to soak parts in, but the same problem of leeching or dissolving the binding material (glue) in gaskets still applies. The best solvent for any organic deposit is ether, starting fluid. But of course highly flammable. I use it to spray out jets and small orifaces. Gregg
Ken Pardon my asking the basics but, from experience, Are you sure you're starting it correctly...retard lever in proper place, chock out,key on, gas on ....gas in tank. It would seem if it was running when parked, you're just missing something....simple. Bob
Ken, I only use ether to clean, not start an engine unless it's 40 below zero, under the 'flash point' of heptane (gasoline) As Bob Smith says, basics. Check for spark first. If spark is there than check fuel delivery. Even if carb jets are clogged, engine should 'try' to start unless flooded. Try to tap lightly on carb float bowl. Check plugs for wettness. If dry try a small amount of gas in carb inlet, just a little. Spark and fuel together will give you something. If engine 'barks' but won't start you must look further inside the carb. You'll get it, Gregg