1996 FORCE 75hp: "throttle control cable" adj messing with idle and reverse acceleration/thrust ??

[surfsalterpath]

1996 FORCE 75hp: "throttle control cable" adj messing with idle and reverse acceleration/thrust ??

When I try to adjust the "throttle control cable" on our 1996 FORCE 75hp it will correct one and mess up the other of idle speed or reverse acceleration/thrust ability. I'm sure it's an easy fix, just do not know how to do it. If I adjust the "throttle control cable" one way I can get the idle speed down to what i think is correct about 8-9k RPMs. But when I do that I lose REVERSE acceleration/thrusting power. When I adjust the "throttle control cable" the other way the idle speed jumps up to ~12-14k RPMs and I gain REVERSE acceleration/thrusting power. What is it that I'm missing here? THANKS!!

 

[Frank Acampora]

The Mercury controls do not have a spring loaded quick connect. The control cables are attached solidly to the linkage. The timing tower usually has a spring attached to it around the center of the bar to ensure a positive return of the carbs and timing.

You must first disconnect the throttle cable. Then adjust the idle speed. 700-750 in forward gear, in the water using the idle stop screw on the bottom of the timing tower.. Usually about 1000-1200 in neutral. Neutral is not accurate but is a good place to start. After setting idle speed move the black plastic slug on the threads so that the end of the cable easily slips over the post when the slug is bedded in its retainer. Then, you should get both forward and reverse equally..

 

[surfsalterpath]

Thanks! I think being a boat mechanic is more technical than being a brain surgeon. Most people have no idea! Sure have enjoyed learning~

 

[surfsalterpath]

........removed the throttle control cable and had the engine running and in neutral. Backed the idle speed screw out as far as it had any control. The idle speed remained at ~1300 rpms. The throttle control cable barrel nut slid right back onto its post easily. When in forward after re-assembly the RPM was ~1100 at its lowest speed. Is there another way to fine tune this idle speed ?? THANKS!!!

 

[surfsalterpath]

No Title

......at the end of the line upgrading hydraulic steering, RemoteControlBox, extra battery with Blue Sea ACR, total re-wire and new fuse block panel and just cannot figure out how to adjust the "throttle control cable" and the " shift control cable" and the "idle stop screw" and the adjustable rod just above the 'idle set screw' attached to the cam. Every change we try always seem to be leaving the "timing tower" just short of returning all the way return to idle and EITHER not enough REVERSE "throw". Weird. Maybe where the "throttle control cable" attachment bar's loose play is the culprit. It is a '96 after all. The pic shows the cam-with the stamped #'s on it, at idle (the line on the cam right at the black lever.) That's good. Going through Forward/Reverse and back to idle leaves THAT line on the cam BELOW the cam meaning more gas and higher RPMs even though the remote control is in idle. At the same time leaving the "timing tower" idle stop screw just shy of returning all the way to stop. Perplexed~

 

[surfsalterpath]

....this is my plan from some advice I received. Sure hope it helps get more THROW' when going into REVERSE.
This will be my plan from your advice. Might be next weekend till I can do this. frown emoticon
#1: Unlock the 'throttle adjustment screw" and adjust it so the 'throttle cam' does not touch the 'throttle arm'
#2: adjust the 'metering adj screw' out 1 1/2 turns --> (this is the scary part)
#3: with the boat in the water (it is) adjust the 'idle screw' (is this the silver slotted screw just below the rear of the throttle arm in this pic?-looks red)? to be at 900rpm in neutral
#4: shift to forward gear-fine tune the 2 metering screws (the Clymer Manual calls them "idle mixture screw" & "idle speed screw" ) to get the idle set ~600-700 rpms.
#5: adjust 'throttle adjustment screw" so the 'throttle cam" lightly rests on the 'throttle arm '
Did I follow you correctly? And thanks again for your advice. You should have seen how much gunk I cleaned out of the bottom of this cowl last week! gasp emoticon

 

[Frank Acampora]

NO, you do not have it correct. This is a mechanical advance system and any setting affects all others. If you try to change any setting without having all systems at a known starting point you will never succeed.

In order to set the timing and throttle, you must first have a known starting point. To do this, you remove the ball link and let the throttle(s) snap closed. You then adjust the roller on the cam screw so that it just touches (is tangent to) the aluminum cam at the single line or between the two scribed lines on the bottom of the cam.

Now you snap the ball link back onto the timing tower and set the length of the ball links and rod so the carbs open fully at wide open throttle. Note that the engine is not running for this.Now, at wide open throttle static time the engine to specifications. With the engine not running set the idle stop screw on the bottom of the timing tower to about 1/2 of its travel. This screw is on the odd shaped "bar" on the timing tower that controls carb opening. Note that in neutral either with the engine stopped or with it running, the carb roller will not be at the scribed line on the cam. Usually it is slightly above it. Note that the control cable may prevent fully closing of the throttles. If this is the case, adjust the cable now.

Now that timing is correct and carbs are synchronized to timing you can adjust the idle speed in the water in forward gear to between 700 and 750 RPM. Lower than that and the engine will tend to stall in gear at idle. Now, also adjust the control cable.

On water testing start with the carb low speed needle at about 1 1/4 turns out from lightly seated. Do a full throttle acceleration from a stop (hole shot and listen to the engine. If it accelerates smoothly no changes need be made. If it "sags" then recovers it is too lean. adjust the needle out 1/8 turn at a time until acceleration is smooth. If it "burbles" and stumbles then clears itself and recovers, it is too rich. Again, adjust the low speed needle IN 1/8 of a turn until acceleration is smooth. DO NOT go leaner than 7/8 of a turn out from lightly seated.

Go to the top of the forum and watch the video "Tutorial"

 

[surfsalterpath]

...thanks Frank!
Tried to find the video "Tutorial" at the top of the forum. Could not locate. ??
Is this a video showing your prescribed procedures?

I found your video on youTube. This vid sounds exactly as you explained above.
This what i should follow?
https://www.youtube.com/watch?v=tDoR64jP5l8&list=PLezUGCtvdiaU2tVVekQE9YKxYzP1139MM&index=4

 

[Frank Acampora]

Yeah! I neglected to say that if you could not access the video to go to youtube.