for 500 ft you give it all the timing it can take, if it rips your arms off now thats not good enough for a grass drag, set it up so it pitchs you off and you can't hold on find someone who can LOL. I'd go 4 degrees. You need everything you can get in the first half of the track, catch up is a hard game to play in that distance.
When you install the key rotate the key to the top, install the key with the step on the left side of the key, install the flywheel and rotate it clockwise against the key, you should have a gap in the slot in the flywheel on the right hand side of the flywheel slot.