Factory set point is 15 Deg BTDC +/- 2 degrees, as I remember I think it was reading at 20 degrees BTDC last fall. I did do the check with the engine warmed up (after driving home from work) and followed all the steps in the book as far as running it at 2k rpm for 2 min. etc. but it wouldn't run at all with the TPS unplugged so I had to leave it plugged in. Now that I'm thinking about it I should probably do the check again - but not tonight, it's the baby's birthday.