Throttle linkage prob/can't accelerate/Merc 25

[nola mike]

I have a 2004 Merc 25 HP. For some reason, it decided to not want to accelerate. Looking at it, it's obvious that the black ramp of the throttle arm, instead of pushing up on the white part connecting to the butterfly, it pushes directly backward (sorry for the terminology, but should be clear on the pic). If I get it started by lifting up the throttle, it works fine. I see no way to adjust the angles of anything without affecting idle speed. I'm sure this is an easy/stupid fix, but I don't see it.

 

[flyingscott]

Is this motor new to you?

 

[nola mike]

No, this was my 4th or 5th summer with it. Worked fine, until it didn't.

 

[flyingscott]

I would look for a broken cable or a problem in the control box. Or one of the many plastic pieces broke.

 

[nola mike]

Nothing appears broken. The force is transmitted from the control box all the way through; if I push too hard that metal arm starts to bend. There isn't any play anywhere. If that black piece angled up more gently, or if I were able to change the angle on that white piece without opening the butterflies it would work fine.

 

[flyingscott]

Something happend. Try taking the control cables off and see if they move smoothly. With the cables off see if the linkages on the motor move freely.

 

[nola mike]

If I take that arm off, the linkage back to the control box moves freely. The white part moves freely. If I hold open the throttle by lifting the white part, everything moves freely. However, If I push on the black part, it doesn't budge (unless I lift the white part slightly, and then everything moves fine). So basically, it shifts fine. If I get up past idle, everything works fine. Going past idle doesn't happen, unless I manually open the throttle a bit and push the levers forward. Again, I can see that the forces on the throttle at idle are sideways instead of upwards.

 

[flyingscott]

Make a video of what is happening

 

[nola mike]

Well, finally got around to taking another look. Started to make a video, and realized that there may be an adjustment to make. I backed off the throttle screw on the right, which had the effect of compressing the silver and white parts together (you can see that there's a groove and pin riding in it, and it's at the end of its adjustment limit). Also lengthened the arm on the left. The net effect is that the white throttle lever rests further up the black "ramp", without actually affecting the position of the throttle. Lastly, noticed on close inspection that there's a small divot on the ramp, which may have contributed to the throttle becoming stuck. Too cold to start it up, but I *think* that this will work. Should have taken an "after" photo...