Mercury 125 HP, can't get to wide open carb shutters

[Mader12345]

I was asked to repost with more detail. I have a year 2000 125HP mercury outboard. Serial #:0t088785.

Engine idles fine and runs well but tops out at 4500 RPM. It should get to 5000-5250 RPM.

I rebuilt carbs, replaced fuel line, replaced fuel pump, etc. Yesterday I began the link and sync process. I adjusted the ide stop screw so that the carb shutters are fully closed. Then I put the control box at WOT (engine off), in order to adjust the stop screw for WOT.

Here is the issue. With control box at WOT, the carb shutters are not fully open (probably 3/4ths of the way). Adjusting the set screw does not make the shutters open fully because the throttle cable will not "travel" far enough to open them all the way. It is as if I need the travel on the cable to increase 1/2".

There is no adjustment to increase the "travel". I confirmed that the control box (which is universal) is installed correctly for a mercury outboard. The throttle cable (Teleflex, mercury) was replaced a few years ago, but I confirmed it is compatible with mercury.

How do I get the shutters to open completely? I'm thinking of buying a new throttle cable but I'm not convinced that is the issue.

Thanks. I'm in Atlanta.

 

[MikDee]

Re: Mercury 125 HP, can't get to wide open carb shutters

Do you have a similar setup inside the control box, a plastic, or metal barrel on the cable that is threaded to adjust one way or the other, to maybe take up the slack there?

 

[Mader12345]

Re: Mercury 125 HP, can't get to wide open carb shutters

I opened the control box to look for that. There is no adjustment there. It's a universal box, and the mercury cable barrel only fits in one place and cannot be turned or adjusted.

 

[MikDee]

Re: Mercury 125 HP, can't get to wide open carb shutters

Is there a setscrew on the cable in the control box? If so maybe you can extend the cable, & reset that. Maybe a few pix might help?

 

[Mader12345]

Re: Mercury 125 HP, can't get to wide open carb shutters



here's the a copy of a page from the control box instructions. I'm using the config on the left side with the mercury cable as shown. No place to adjust anything.

 

[MH Hawker]

Re: Mercury 125 HP, can't get to wide open carb shutters

If it has no adjustment then I would **** can it and get the right controller. You cant beat the correct parts.

 

[JustJason]

Re: Mercury 125 HP, can't get to wide open carb shutters

...

 

[Mader12345]

Re: Mercury 125 HP, can't get to wide open carb shutters

I have to check the play tonight. Yes, I am installing the throttle cable at the engine by the book. I have the factory manual.

@ MH Hawker: I did not think there are any control box adjustments from any manufacturer except for friction. If you can point me to one where I can adjust cable travel, I would be all over it.

 

[Mader12345]

Re: Mercury 125 HP, can't get to wide open carb shutters

I have to check the play tonight. Yes, I am installing the throttle cable at the engine by the book. I have the factory manual.

@ MH Hawker: I did not think there are any control box adjustments from any manufacturer except for friction. If you can point me to one where I can adjust cable travel, I would be all over it.

 

[MH Hawker]

Re: Mercury 125 HP, can't get to wide open carb shutters

Out of the book. Yours may be a bit different but this is how.

 

[MH Hawker]

Re: Mercury 125 HP, can't get to wide open carb shutters

and

 

[Mader12345]

Re: Mercury 125 HP, can't get to wide open carb shutters



I did the Lync and sync again and I had better results. Pic on right is with control box to wot. Pic on left is me manually advancing the carb linkage. It's a pretty small delta to full horizontal but the way the factory manual is worded I thought the throttle cable would have too much travel. As it is the wot set screw has no purpose.