mower was hard to start when wet, found out it was the coils on both sides. spryed them 3 times and engine would die? now put 2 new ignition coils on and mower will turn over for 30 seconds to a minute and backfire then the next turn it will start fine and cut, and once it gets cold again it does the same thing. dosent ack up at all while im cutting. i adjusted the valves over the winter, i'm wondering if they need to be readjusted again? shouldn't be the shear key if it runs after the back fire right. maybe it because it just got too cold the last few days since i put them on. is there a clearence to go by for the coils, there is enough wiggle room to where if the are up too close they rub the flywheel.