Mercury 50 HP ELPTO Throttle Control Box

The throttle on my 50 hp Mercury outboard is getting very stiff. The plastic is also starting to crack and the handle itself is very loose. The actual throttle lever moves 3 inches or so from one side to another (not up and down with the throttle, think side to side). I think its about time for a replacement. Where is the best place to source a new box? My initial though would be to leave the cables and just insert them into the new unit. I am open to opinions on past replacement methods. Thanks for the help. Photos below for reference of what box I need. Anyone with a thread about their personal replacement - a link would be awesome.

There's a bolt that goes through and holds the throttle arm to the box, it sounds like yours might be coming out. The grip handle can be replaced individually, I did that on mine. The throttle stiffness can be adjusted by the plastic knob on the front, but it might be the grease inside has dried up over time. You can take it apart, clean everything, re-grease it and you should be good. Just take a picture of the position of all the cables, wires, etc. so you know how it goes back together.

Couple things that I also do are:

(1) disconnect cables (one at a time), lift moving end up & weep in Breakfree CLP and

(2) I put a small homemade cover made out of Sunbrella fabric over anything that I don't want the sun to 'bake' and damage or destroy ... like the control box, when not in use.