here's where I'm at, before I tried starting my car the thing would roll a few feet when pushed on ground. I tried starting it and it ran for about 30-40 secs and stalled, I made some adjustments and it would run and stall. Anyways while it was running the wheels were spinning very fast but if I put it on the ground it would stall so I tried rotating the wheels by hand and now its like the both won't spin at same time is that normal?