Help-carb back fireing

[mud.man.rj]

Just back from camping at the lake, nice you have it sorted out, I usually use a vacumn/fuel pressure gauge and hook it up to full/manifold vacumn, adjust my timing full advance till it won't go any higher on vac gauge, which is also where it will start to run bad then retard distrib (clockwise) about 2.5" on the gauge, so if max is say 18 back off til 15.5" and should pretty well be as close as your going to get it for a base. Under most cases won't have to change it at all, it takes into consideration the shape of the engine, any cam or carb. A vacumn gauge is really cheap and handy to hv around. Glad you got yours sorted out, good news.