How did the motor run for you last season ?----Install your own timing pointer if it is missing.-----Timing on these just does not go out of adjustment.-----What is your motor doing / not doing.----Why do you feel there is a timing issue ?
A " new to you motor " ----Bad switch / bad starter is a sign.----Do a complete evaluation before you spend more $$$----Post actual compression values.----Running with tested VRO or 50:1 mix ?---Does spark jump a gap of 3/8" on all leads ?----Water pump impeller replaced ?----Overheat horn tested?