Stiff Engine Controls

[Slipperman]

My boat has a Vetus engine control working a Yanmar 3YM30 engine with a sail drive. The control lever has always been very stiff when used with the engine in gear ie under load, and it seems to be getting worse. When in neutral, the throttle action is light and smooth. The cable is a solid flexible rod type, and I can't see anything which is pressing on it which might cause a problem. I have tried lubrication, but it is quite difficult to get any into the cable itself.

I spoke to a Vetus man at the last Southampton boatshow about this, and he said it was fairly normal - said something about a cone shaped clutch which I did not understand. However, I have just come back from a week's sailing in a boat with the same engine but a Morse type control rather than Vetus - it was as smooth as silk! The only difference, which I guess may be relevant, is that the boat with the Morse control had a conventional shaft rather than a saildrive. Can anyone shed any light - I would consider swapping to a Morse unit if it is going to do the trick but do not want to waste money if it is the saildrive that makes the difference.

 

[Deleted member 36384]

I have found that deterioration of the inner core results in stiffness, especially when under load. I think what happens is that dampness eventually gets in and that any dust or salt crystals begins to jam up the cable. Lubrication probably just makes the situation worse as it helps bind together more crud. The reason I believe is a relatively close tolerance between the inner cable and outer coverings which make the cable / rod system stiff enough to push / pull. Also some nylon inner sheaths may swell with moisture over time making the situation worse.

 

[scottie]

The basics of the control are that the throttle lever and cable work at all times but the gear selection is only when it's not disengaged .

the load on the throttle is unchanged either way

When the gear is selected then you get the additional load plus any load /drag from the gearselector or gear cable.

Cables should be the correct length with long strait runs tightish bends rather than long sweeping bends.

Try disconnecting the cables in turn check that the cable allows full throw to be achieved both throttle and gear

If you wish you can get better quality cables from most suppliers which may minimize the problem

Cables are non serviceable check the rod ends are straight free from gunge and that there is no external damage to the outers do not try to lubricate

 

[PCUK]

Cable adjustment incorrect. Gear not going fully in and then putting pressure on the throttle cable.

 

[colvic987]

disconnect the gearbox linkage, and see how easy it is to engage, then you will know how bad your cables or control unit is.
I have just removed my gearbox for sterngear renewal, and was amazed how easy my gearbox linkage moves, compared to when its connected to the linkage cables and control. it will be investigated when it all goes back together.

Maybe replacement is the only option

 

[Topcat47]

Scottie said "Cables should be the correct length with long strait runs tightish bends rather than long sweeping bends." I disagree.

The tighter the bend in any bowden type cable, the higher the friction will be. Ideally the curves should be as large a diameter as possible. The sheathe ensures the inner cable moves the appropriate distance at each end, however the cable is run. With the cables disconnected, try with different bend radii and you'll see what I mean.

Don't be tempted to shorten the cables either. If they look like they're fouling anything important, clip them up out of the way.

 

[scottie]

Straight runs with short circumference bend is more efficient as it decreases the drag even if at first it seems wrong.
Don't clip cables up unless to stop fouling as it causes more drag through s bends

 

[KellysEye]

When ours got stiff I slowly poured 3 in One oil down the cable tube at the gear lever end. it worked.