Starting and Running Problem...

the backfire is from the valves being to tight,like 340 dave was saying,with the engine warmed up adjust the valves to .010 on the intake valves and .020 on the exhaust valves,and loose the lawn mower air cleaner in favor of a stock replacement that lil' dinky thing is choking the fuel mileage right out of the lil' slanty.you can put an ad in the wanted section for a stock air cleaner and valve cover breather,and from the looks of the fuel leakage the carb should be rebuilt and a new fuel filter. the rocker shafts should be tightened but the rockers themselves get adjusted,use a flat feeler gauge for valve adjustment.pm me if you need more help on this or you can get a service manual for the car or borrow one.hope this is helpful and good luck with it

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