Hey, I saw this post and had to reply. I live in Kenosha WI and I purchased a Cobra S4 from the same place. Mine did the crazy high speed wobble to and I did everything I could to the alignment to try to change it. My frame was bent in a few places, so I figured that was the issue. I did ALOT of upgrades to mine before I sold it. I installed the big head kit, with changing the piston head, Pocket bikes unlimited's bad *** exhaust, performance carb, i changed the reed and spark plug. It made a huge difference and looked awsome....especially with the torque. Email me if you have any more questions or some pics of my old
cobra....nvmysi@hotmail.com