Engine throttle wont stay where set

[Tanzersailing]

Hello everyone,

I have a Tanzer 8.5 sloop with a Yanmar 2GM powering it.

I am having an issue with my throttle not staying where i set it. As I press the throttle stick down in the cockpit and throttle up the engine, if I let go of it the throttle goes back to idle position quickly.

I'm wondering if I can adjust anything to slow this down or have it so the throttle stays where I set it. When under power I have to hold the throttle with one hand and the helm with the other the entire time otherwise the engine goes down to idle speed.

I've attached a photo of the side of the engine where the throttle cable connects to it.

[mcpusc]

they sell a "throttle cable brake" that adds some friction to the cable. it clamps over the cable at the control end & keeps the throttle from creeping.


you may find that you already have one & it just needs adjustment, that was the case on my boat.

[Bowdrie]

The common fix is a simple part from Morse Controls.
https://www.fisheriessupply.com/mors...-cables/044386

Out of stock at that location but should be an easy part to find.

[Topsailb]

I had the same problem. A cable clamp tightened on the throttle cable as near the control (not the engine) as possible stopped the slipping. Not so tight that the throttle barely moves-it took a few tries to get it to hold but not bind the cable.

Some choices to consider:
https://www.tractorsupply.com/tsc/pr...steel-n830-314
https://defender.com/en_us/wichard-w...s-cable-clamps

[Orion Jim]

Originally Posted by Topsailb

I had the same problem. A cable clamp tightened on the throttle cable as near the control (not the engine) as possible stopped the slipping. Not so tight that the throttle barely moves-it took a few tries to get it to hold but not bind the cable.

Some choices to consider:
https://www.tractorsupply.com/tsc/pr...steel-n830-314
https://defender.com/en_us/wichard-w...s-cable-clamps

Friction is friction, no need to be close to the throttle under anything but special conditions. Anywhere on the cable where you have easy access is the norm.

[kmacdonald]

A spring on the throttle lever on the engine is good and won't make moving the throttle harder. It will make it easier in fact. Some of the throttle return springs can be adjusted also. Take the cable off the engine throttle lever and see how hard it is to move. You want to lessen that return force. The throttle cable clamps work but makes it stiffer to adjust throttle.

[NorthCoastJoe]

There should be a friction adjustment near the throttle handle. Tighten the nut on the throttle lever axle.

[Cheechako]

Yes, there is often a tensioning method in the binnacle, do you have a binnacle?. I see no return spring on the engine so am surprised it is backing off so readily. There's often enough tension in the cable to hold it pretty well.
If you have just a throttle/shifter in the cockpit and no binnacle, I think those can be tensioned also. Usually a friction screw on Morse or even on single handle powerboat type controls.
DO you know the maker of your controls if no binnacle?

[kmacdonald]

You need to add a spring on the engine to throttle lever. It needs to oppose the return spring force.

[Topsailb]

Originally Posted by Orion Jim

Friction is friction, no need to be close to the throttle under anything but special conditions. Anywhere on the cable where you have easy access is the norm.

I agree that friction is friction; however, how it is induced and where it is induced matters. Using a cable brake induces friction at a specific point. Too close to the engine causes the cable to bow inside the sheathing and puts unnecessary strain on the throttle control components as the throttle handle is a lever moving the cable. AMHIK-

[Bellinghamster]

I 3d printed a thermoplastic urethane (TPU) friction sleeve that replaces the little black seal on the end of the cable sheath (friction adjusted by a small zip tie around the barrel. It added just the right amount of friction to keep my throttle from creeping down. BUT... I put it on the engine end of the cable (because it was easy to reach there!). The "slop" in the cable and connections between there and the binnacle adds an undesirable loose feel to the lever. I plan to move it to the binnacle end of the cable, which should improve the user experience . The return spring on the injection pump will always pull the cable slack so lever-to-throttle response should be improved.
I'm happy to print a couple more if anyone is interested in trying them (or provide the model if you have access to a 3d printer)

[kmacdonald]

Friction on the cable is a workaround, not a fix. Think about it and do it right. Unfortunately engine marinizers often skip this step. Increasing force to move throttle is not good for the cable or the "feel" of the throttle lever.

[Bellinghamster]

Originally Posted by kmacdonald

Friction on the cable is a workaround, not a fix. Think about it and do it right. Unfortunately engine marinizers often skip this step. Increasing force to move throttle is not good for the cable or the "feel" of the throttle lever.

My problem is there is no friction adjustment at the lever, or easy way to add one. The lever (and cable) move rather freely and the throttle return spring returns the throttle to idle. The "Morse" cable-smashing friction device seems abhorrent to me (simply drives a bolt into the side of the cable sheath, smashing it).
The injection pump has a return spring for a good reason - to cut the throttle if the cable ever breaks or cable connections fail, so I'm not interested in removing the spring or countering it's force with another spring. Adjustable friction at the binnacle throttle lever would be best, but again, there simply isn't an easy/good way to do this on mine. Adding cable friction at the binnacle end is next best.

[kmacdonald]

The spring is on the inside of the governor.

[kmacdonald]

The return force is unnecessarily large for most marine applications. A lighter spring would be ideal. Your workaround is the best I have seen and should work well.