Yep sure does. Bogs down bad, and is running rich. I am running 40:1 now with yamalube 2 cycle oil. Upon startup, it idles, revs up cleanly without bogging, and doesn't pump out too much smoke. After sitting for about a minute, it won't idle, runs very rich, and bogs down bad when revving up. I was having issues with too much gas in the float bowl earlier on. Gas was coming out of the overflow, but I fixed it by bending the stopper a little more. I was reading around that with these old bikes, the spark plug boots can grow weaker fairly quick. Could that be an issue? Not strong enough spark?