Adjusting throttle cable - recommendation required

[Spudwynk]

Hi

We're moored at Sawley Marina and need our narrowboat throttle cable adjusting.  Does anyone have any recommendations on a professional who could do this for us please, ideally in-situ at the marina

 

Thanks

[Tracy D'arth]

You could ask at the marina?  Why does it need adjusting? Could it be about to snap?  Pains me to say, but RCR?

Edited October 9, 2022 by Tracy D'arth

[Tony Brooks]

I don't know what is so difficult doing it yourself as long as you are physically able and there is enough adjustment at the engine end. Even if there is not enough adjustment there it is not too difficult to adjust most at the control end.

 

Just remember to put the control in slow ahead or slow astern before attempting the adjustment.

 

Happy to give procedure if you are interested, but what makes you think it needs adjusting,

[Spudwynk]

10 hours ago, Tony Brooks said:

I don't know what is so difficult doing it yourself as long as you are physically able and there is enough adjustment at the engine end. Even if there is not enough adjustment there it is not too difficult to adjust most at the control end.

 

Just remember to put the control in slow ahead or slow astern before attempting the adjustment.

 

Happy to give procedure if you are interested, but what makes you think it needs adjusting,

When we go unto forward throttle it does nothing for 45 degrees then runs into quite high revs and you have to pull back to slow to the revs you want

 

Have been told not to touch myself as we know nothing about engines and gearboxes and it needs a professional 

 

There's only so far I'm prepared to take DIY as a novice owner 

[chevron]

Depending what gearbox you have sounds more like the gearbox maybe slipping. personally i would check the level of gearbox oil especially  if it’s a box with clutch plates.Then the adjustment of the gear cable and movement of the lever. It could have come loose or the cable might be failing. 

[Paul C]

Just walk into the marina and ask them

[Mike Hurley]

If you cant adjust a throttle cable then your boating life is going to be mighty expensive. As stated above, ask in the marina.

[Tony Brooks]

I can understand why someone who is not very practical and new to boating would be reluctant to touch this but --!

 

The description of the fault could easily describe a gearbox fault as Chevron said. Low oil level on a hydraulic box or worn clutches on a mechanical one. A photo of the box would allow identification.

 

It could also be the one of the two outer cable clamps loose so a visual check at both ends of the cable to see if the outer moves as the control is moved (it should not) should not be too difficult and will not disturb anything.

 

If the throttle lever on the engine or the one in the control is loose on its pivot it might give these symptoms. Again a visual check while the lever is being moved would not disturb anything vital.

 

It would be a good idea to check the trunnion (pin) where the cable fixes to the lever in the control and the hole it fits into is not worn, especially if it is an old boat.

 

There are two holes for the cable trunnion inside the control, and you could get excess lever movement for the number of revs if it is in the inner of the two holes.

 

Personally I very much doubt it is adjustment unless it is a new cable badly fitted or the boat is very new to the poster. There are a number of ways of attaching the cable to the engine lever so for further advice, if wanted, we really need to see a photo of what is there.

 

[Tony Brooks]

A further thought. I was thrown by the topic title.

 

The symptoms would also apply to a gear change cable outer floating about so the checks in my previous post need doing on the gear cable as well.

[Mad Harold]

Strongly recommend that you learn how to do basic maintainance yourself.

With professionals charging £45+ per hour+ VAT if you can find one, you will very soon suffer the curse of the empty wallet! 😭

Much free advice is available on here, and as Tony says photos of your problem area will be of enormous help to diagnose the problem.

[David Mack]

13 hours ago, Spudwynk said:

When we go unto forward throttle it does nothing for 45 degrees then runs into quite high revs and you have to pull back to slow to the revs you want

Get someone to move the control lever into forward gear while you watch what happens at the gearbox end. You should see the actuating lever on the gearbox move just after the engine revs start climbing. If this is what happens then you probably have a gearbox problem. But if the lever does not move until the engine is up to quite high revs, then the cable needs adjusting (or maybe the control lever unit).

[jonathanA]

In my experience of marinas if you lift the engine covers and get a toolbox out you'll soon have lots of people offering advice...  a bit like here working out who to listen to is the hard bit. 

 

Seriously have chat with a few of your neighbours and try to work out who is knowledgeable and might be prepared to help you. Best way to learn...

[Spudwynk]

1 hour ago, David Mack said:

Get someone to move the control lever into forward gear while you watch what happens at the gearbox end. You should see the actuating lever on the gearbox move just after the engine revs start climbing. If this is what happens then you probably have a gearbox problem. But if the lever does not move until the engine is up to quite high revs, then the cable needs adjusting (or maybe the control lever unit).

The engine revs jump when moved into forward gear from tick over when pointing up to lots of revs at 45 degrees forward. Then you can move the throttle back towards centre and the revs drop slowly in line with the throttle movement

Will look this weekend when we go back 

[Tony Brooks]

1 hour ago, Spudwynk said:

The engine revs jump when moved into forward gear from tick over when pointing up to lots of revs at 45 degrees forward. Then you can move the throttle back towards centre and the revs drop slowly in line with the throttle movement

Will look this weekend when we go back 

 

That might indeed mean the throttle cable is mall adjusted. On most but by no means all controls the control end anchor for the throttle cable outer is on a spring-loaded slide. You adjust the cable with those controls in the slow ahead or astern position. Then as you move the lever to the central position (neutral) the spring on the slide compresses allowing the slide and thus the cable outer anchor to move. The effect of this is that as you move from neutral to slow ahead/astern the anchor slides rather that the cable inner moving, Thus you get no throttle opening until you are actually in gear. It sounds as if you are getting throttle opening as you move from neutral into slow ahead/astern.

 

This is a very common mistake that even some "engineers" make,

 

Those controls that do not use a spring often use a cam acting on a rod or bar to move the cable anchor for the same effect. If that rod breaks you can get the symptoms you describe. A photo of the control may help identify  which typw you have.