Hey, team. Why is my 1993 900SS destroying the vertical cylinder spark plugs? As previously documented I changed the plugs, about 40 miles ago. Since then I've had to change to the spark plug in the vertical cylinder twice! For the last year, when i have had the opportunity to ride it, the bike has been a bit lumpy up to about 1/2 throttle. This prompted me to change the plugs and clean the carbs. I know I need to give the keihin carbs a proper service. I'm pretty sure at the very least the float valves need replacing and probably the emulsion tubes. But that said it wouldn't be the fueling causing the spark plug to fail. Would it? Is it more likely to to be the coils and why?