I was messing with it a little and have two new data points. When I quickly pull the throttle, the engine quickly cuts off. No stuttering at all.
The other one is a little strange but may shed some light on the problem. I somehow got it to run for a bit on full throttle but after 15 seconds or so, it would start to die so I had to let up on the throttle to keep it going. I did tbis a few times......it would run on full throttle for a bit but then start to die until I let up on the throttle.
I finally just held down the throttle and it ran on high for 20 seconds or so and then it died. [break]. I wanted to be sure I was describing it properly for this post so I started it up, let it warm up a little, rev'd the throttle a bit and then fully opened it up and it ran and ran and ran and never cut out!!!
I haven't tried it in dirt yet, but does this mean that there was some sort of blockage that was cleared?