Muffler turns red hot, and lack of power 18.5 briggs
I have a craftsman 18.5 intek plus model 31p777/ type 0348e1/code 010406ze. It had a bent rod when i got it and found the valve was stuck solid. I reused the valves and ground and seated them and set intake at .004 and exhaust at .009, i also replaced the key at flywheel.it starts but has low power and muffler starts to turn red hot. What am i doing wrong. Has new spark plug, should i buy new valves? These didn't have any chips on them. And i lubed them and they slide nice. Its like exhaust valve is leaking and gas is possibly getting to muffler. Or??