I had that exact lock deal on my YM2002, I removed it and made one I could slide up and down so I could set how high I wanted to lift. My book doesn't say anything about the purpose of it. How about swiveling it out of the way and with tractor running "slowly" raise handle past it and see what happens. Nothing on mine except the lift goes higher. As long as your system doesn't begin to overpressure I can't see how raising it past there could hurt. As far as your starting goes, I believe everything is good. In my opinion you are going to need a strong battery without a compression release. I'm not sure where it is you are energizing the heating element. Is the middle light the one that goes with it? Just didn't seem you had to wait long enough for it to heat up before busting off.