I have had to pull apart my Briggs and Stratton engine Model #92908, type:5389, code/; 89042104 as the oil seals needed replacing. I seem to be able to get the thing bact together but I am unsure of how to mate the crank and cam to assure correct timing. I don't have a manual or anything so am unsure also of the airgap settings etc. If anyone can help, I would be eternally grateful.