Got a McCulloch Mac 100 series Eager Beaver, about 25 years old, ran a few minutes last week, died and won't restart. The carb. diaphragm and gasket are hard/distorted but I can't figure out the gas tank venting. The parts book shows a square piece of cork or felt maybe that goes over the filler and under the saw body and call it a vent but there's no hole in the tank, no gasket in gas cap either. Maybe they're counting the slight leak at gas cap as a vent and using the square piece of cork/felt to soak up the gas spill. Hooked vac. pump to the tank and it slowly goes back to zero., don't know what would be considered normal. Should toss it but might try a carb. kit.