Merc classic 50 throttle adjustment help

[slwagner3175]

Have a 88-89 classic 50 (45 hp) Merc, I had some work done last fall on control box since I couldn't throttle in neutral. got that fixed, but now doesn't seem to throttle to WOT in forward gear or don't get much in reverse either. Wondering how easy/difficult it is to adjust for the do-it-yourselfer with some common sense, or is this something I need to have a marine specialist look at? Thanks.