1970 Starcraft Holiday 18ft Aluminum boat

Description

1970 Starcraft Holiday inboard/ outboard 120 horsepower 4cyl mercruiser 2.5l.
Hull of boat is in overall good shape.
Had the boat in the Delaware river a few weeks ago week, no leaks.
Engine and outboard seem to work well, replaced water pump runs cool.The main issue I am having is the shifter/ throttle cables do not seem to be adjusted right. Inreverse the boat will rev-up and go at a high rpm but to throttle forward it will only go to 2000 rpm and put along. not a boat guy and don't have time to work on it.
Trailer has almost brand new tires, new lights/ wiring and new hub bearings.
I have a NJ title for boat, trailer can be sold with bill of sale.