Ok, my savage 4.1 wasn't shifting into second gear, it was tuned properly, it ran very nice, top speed was only 20mph, so I wanted to get it to shift into second gear, so I watched a video on YouTube of how to do it, when I adjusted the screw I wanted to go test it out so I brought it oudside and put the roto start to it and try starting it, nothing happens the roto start spins but the piston doesn't.. It's an older truck I think 1 or 2 years