After watching the video posted about changing the spring and reading the pamphlet that came with the spring I began the job and failed to notice the relationship of the slot in the throttle shaft with the tick marks on the plate. (Not clear in either reference) Everything was stuck together pretty well with residue and it came apart fairly difficultly. Anyway, am I up the creek on this and need to take it to a pump shop, or is there a basic setting to begin with. The pump has 160,000 miles on it but ran well the last time I started it. How many miles do most get before needing a rebuild. Thanks for the info.