Yeah it`s a locked dist., but the timing is controlled by the fuel inj. set up. It`s at 21 initial. Had it at 22 and it didn`t want to start when summertime hot. It was totally new and didn`t have much run time on it then tho. I have been thinking on bumping it a little more now that its got about 450-500 miles on it . I don`t get around to messing w/ it a whole lot, especially w/ the weather this winter. --thanks for the reply-