PS, anyone have any hints on how to remove excess carbon from the ex valve using some sort of solvent or something? (i woudnt want to start scratching away using a scraper etc in case i damage anything).
I use a propane torch - heat the carbon until it turns grey/white, then it wire brushes off. If you don't have a torch (or access to an oxy set), oven cleaner and a lot of elbow grease will do it. Soaking in water overnight will soften the stuff, too.
One of the tricks my brother & I used to use in the (bad) old days, was to spray water into the carby (whilst the engine was running), let the engine recover, then do it again. Repeat a few times, then go for a drive around the block. The difference it made to old side-valve four cylinder cars was amazing. (showing my age a bit, there!!)
