Newbie - Throttle Cable Adjusting

[JasonMay]

Hello.

I just put $800 into a 77 mercury 50hp thunderbolt, inline 4 cylinder to make it "good as new" from a local shop.

The throttle cable moves at the engine when I push the throttle lever down, but there's no tension or increase in rpm's or speed until I have the lever about 80 percent full throttle. As a result, my 50hp runs like 10hp. The shop said it must be my gear box, and they'd fix it (for more $).

I've put as much money into this motor as it's realistically worth (when it runs right) and don't want to put more into it if I can avoid it.

Can anyone give me a newbie friendly tutorial of sorts on how to adjust this? It shifts into gears fine and it actually runs great, but I'm only getting about 1/5 of the power out of it than I should.

Thanks!!

 

[JasonMay]

Wwll, I figured out the barrel nut thingy, I tried taking it nearly all the way forward and back, but noticed no difference. Is it possible I need to adjust the shifter barrel nut, so it switches gears quicker?

I'm really trying to avoid putting a bunch more money into this, if possible.

 

[JasonMay]

I should add that the shop replaced the power pack, trigger, and carb kit. Seems to me when they ran it, even if just on water muff things, they should have noticed it sounded like a 10hp and not 50hp