I just put in an new SBT 787 in my jet boat and new carbs as well! Sooo the timing seems to be still off....I learned how to do it on this site and put in a new rotary valve form WSM ? hmmm it wont line up exactly right? it seems to be off just a little bit. The new motor turned over hard but I got it to start,timing is still off!. Has anyone tried a Carbon Tech rotary valve with any luck? and how about trying a different pitch?The one for my boat is a 159 might a 163 work as well? or would it need to be used with a hi performance pipe? Thank you