Sorry; somehow missed this, JP.sorry for derailing the thread, but... more details on how it fcked you please?
Working on a bike with a non-stock cam, and even on exhaust stroke the bike made enough compression to fool me into thinking I was on the compression stroke.
Spent a long time on it, and finally just decided to follow the manual blindly, just for kicks, and it fired right up.
I don't use my thumb any more. I use the manual.