Just within the last day, I've noticed some popping (kind of like a spitting sound) coming from the left side of the engine. It's been somewhat inconsistent but it happens sometimes upon applying throttle from a stop and at slow speed decel. Maybe I just don't notice it at higher speeds. Seems to be at the left carb but I'm not sure. When it does pop it stinks like something burning. I've been reading other posts and I wonder about vacuum plugs - I've never changed mine - but I haven't seen mention of the burnt smell after popping. About a month ago, I added Sea Foam to the fuel (1/3 of the can per fuel up until the can was gone). Everything else seems normal and I don't notice any performance changes. Nearing the 6000 mi mark and had it in for the 4K checkup at the dealer this past spring.
Any help would be appreciated.
