I've got a Evinrude 9.9 model: 10624H ser.# C75237. I beleive it was made in the mid '70s? It's old and used but not abused but the pull start assembly is in a bag and the lower end needs a clean up. I'd like to know the year it was made and a repair manual for this model. I had it serviced a couple times but the timing keeps drifting and my repair shop has basically blown me off saying its not worth spending any more money one. It was my first motor, I just don't have the heart. Any help would be greatly appreciated. I just found you guys last week. I thought I was alone out there.