Before I tear my engine apart....I was ridin the other day for about 5 minutes, all sudden it just bogs down real bad, has power, but barely. Didn't really notice anything, let it sit for a couple days. Drove around earlier, did the same. Changed the carbs (I had stocks on, I put my new 28mm on) and checked for spark just to make sure. Then changed plugs to be on the safe side. New carbs, new plugs, and still spark. Changed the fuel lines to some new stuff and tried again. Ran fine for not even a minute and blah, did it again. It's only running on the left side. I dunno what else to check. So before I start ripping stuff out, anything else I could check on or double check on?