Mercury 100 throttle cable adjust

[beckoning]

I searched for applicable prior posts and found none.

As you can see from the photos, I have a late 1980's (1989?) Mercury 100hp oil injection 4 cylinder. It starts and runs great. At speeds below 2,000 rpm, it runs on 2 cylinders (presumably to save gas?). At speeds above 2,000 rpm, it kicks to 4 cylinders. That all works well. My PROBLEM is the throttle cable seems to have stretched and I cannot figure out how to take up the slack or adjust the cable. Presently, I need to move the throttle stick to 11 o'clock for the rpms to increase above idle speed. A few years back, the engine speed began to increase as soon as I moved the stick forward. In the past, at full throttle (9 o'clock), the motor would reach 6,000 rpm. Now, at full throttle, it will only reach 5,000 rpm....on a good day. The motor runs fine, so I certain it is not a performance problem, but a linkage problem. I think the linkage needs to be adjusted, but I'm unwilling to tear into it without some confidence and knowledge. I only use the boat and motor for fishing on Lake Michigan, so speed is not critical, but it would be nice on a calm day to really move if I want to. If you look at the attached photos, I believe from moving the throttle lever and watching what happens that the lower horizontal lever is the throttle, and the upper horizontal lever is the cam operated lever to kick in the 2 additional cylinders above 2,000 rpm. How to I take the slack up in the throttle mechanism?

Thank you in advance for your assistance.

 

[Texasmark]

In picture #1 is the black plastic cover (with 2 screws) that holds the adjusting barrel in the engine mount. Remove it.

Remove the cable barrel from the slot and place the engine in N. Then with the barrel out of the slot move the remote to N. The barrel should be inline with the slot and if so, the cable is already properly set, just reinstall it and look elsewhere for your problem.

If not lined up, spin the barrel on the threaded part of the cable until it is lined up and reinstall in the engine mount. This will solve your problem if alignment only was the origin.

Yes on the 2+2 kicking in all 4 around 2500 rpms and above.

If you are using the Quicksilver 2000 or 3000, which are popular on bulkhead and in bulkhead mounting controls, you do have some slack between N and when the throttle cam activates a change in throttle. 11 O'clock sounds about right. The idea is for you to be able to complete a shifting operation before the rpms are increased. If that's your only problem and N on the control is N with the engine, leave it alone.

 

[beckoning]

No Title

Your reply is very helpful, however I am confused when you state "In picture #1 is the black plastic cover (with 2 screws) that holds the adjusting barrel in the engine mount. Remove it.". I looked at the plastic cover closely, and, unless I'm looking at the wrong thing, there don't seem to be screws, but rather rivets. If you see photos #5 and #6 attached, that's what it looks like to me. Photo #7 shows where the cables attach. Should that be where I detach the cable?

Any help you can provide will be appreciated.

 

[emckelvy]

Actually that piece has a slot in one end, and the other end has a hook that snaps into the "rivet". As I recall the top end unsnaps, so take a real close look at it and I bet you'll be able to see how it works. HTH..........ed

 

[Texasmark]

Yeah, sorry for the misnomer. Has been awhile since I took mine off. Mr. Mcklevy nailed it. The rest of my post is correct. In pic #3 remove the top nut and the cable comes off, but you don't need to do that. Once you twist the cap out of the way, if you pull out your rubber environmental seal where the two cables enter the cowling, easily done, the cable will move to the side and the barrel can be accessed for rotation and visual alignment. This is easier to get an exact measurement than removing both the barrel and the end of the cable. You just push it out of the slot, setup your engine and remote, check the barrel location, move till it lines up and push it back in.

 

[beckoning]

Thank you Mr. McKelvy and Texasmark. I'll take a closer look. I'm on the edge of thinking "if it ain't broke, don't fix it". I can live with 5,000 rpm max, so if it looks like I'm getting in deeper than I should, I'll back out. Bottom line is that reliability trumps performance for this boat.

 

[Texasmark]

Well pull it loose as directed, position the control and engine in N and look at the barrel. That will take you all of 2 fingers and 2 minutes. Give us the answer as to where the barrel is. Will tell you right now, if the barrel is not lined up with the slot, it's another 2 minutes to spin it till it is, push the barrel back in the slot and close the black plastic cover!

 

[beckoning]

Texasmark and Ed,
Although I won't be able to test until I'm in the water (I'm doing spring prep on the trailer), I think I improved the situation. I did as you both suggested. I saw how the clip opened and snapped it opened turning it clockwise. It was easy to figure out how to adjust the barrels. The upper barrel was pressing towards the front of its slot with the control in N, thus when it was removed from its slot, it would not go back in; it jumped forward. With the barrel out of its slot, I turned the barrel on the adjustment arm 2 turns, and it easily slid back into its slot, thus shortening the cable's distance from the barrel holder to the end of the cablel, thus (theoretically) reducing the remote throttle lever throw so the engine speed should come on a tad sooner and when the lever is at 9 o'clock, the throttle will be more open, closer to 6,000 rpm. It is easy enough that I can perform this with the boat in its hoist, where it stays until November 1.

Thank you both.

 

[Texasmark]

I was thinking about this while I was supposed to be thinking about sleep last night and something dawned on me. I must have had a senior moment or brain pfart when I first answered your post. I do apologize.

I answered your question as if you were having a shifting problem only but the throttle needs to be addresses also.

In that regard, remove the barrel on the throttle cable, as you did with the shifter and then set your remote control shift/throttle arm to the full down F gear position as if you were in F gear and wanted wide open throttle (WOT). Grasp the movable end of the cable at the engine (still connected to the engine's linkage) and push the engines throttle linkage back as far as it will go which would be the WOT position of the engine's linkage. Again, look at the position of the barrel. If not aligned with the slot do as you did with the shifter and spin the barrel till it fits easily. Now your control and the engine linkage will give you all the performance the engine can deliver under the current operating conditions.

 

[beckoning]

No Title

Texasmark,
Good catch. I see the logic. I will try it. It does appear that adjusting the barrel as you initially described will begin to accomplish the same thing, but not the extreme of adjusting the barrel at WOT. Now that I've figured out how this all works, I think I can do what you recommend, even solo since I can put the shift lever at 9 o'clock (WOT) and measure the barrel at the engine. Please look at the 2 attached photos from above. Do I adjust the upper barrel (I think that is the correct one) or the lower barrel?

 

[Texasmark]

Texasmark,
Good catch. I see the logic. I will try it. It does appear that adjusting the barrel as you initially described will begin to accomplish the same thing, but not the extreme of adjusting the barrel at WOT. Now that I've figured out how this all works, I think I can do what you recommend, even solo since I can put the shift lever at 9 o'clock (WOT) and measure the barrel at the engine. Please look at the 2 attached photos from above. Do I adjust the upper barrel (I think that is the correct one) or the lower barrel?

As I recall and see, the upper, the one that is on the throttle cable. Actually my first response was for the shifter cable and really would have nothing to do with the throttle cable. Again, sorry for my brain pfart on getting on the wrong horse there.

Mark