Refurbishing control gear

Andy Young2 · 06 October 2009, 06:29

I am refurbishing a Libra 6.5m rib which has 2 x PTT Yamaha 75s. The boat has been unused for a while and left in 50 degree heat. The control gear is two 703 boxes 'back to back'. The control levers are very stiff (when lifting red slide and moving lever forwards) and there is a clunk when forward gear is engaged on tickover. Can anyone advise whether I can buy a service kit for the control boxes and how easy they are to strip and recondition.
Also is the clunk on engaging gear likely to be wear in the gear box or a case of a competent person adjusting gear linkage and/or control cables
many thanks

Poly · 06 October 2009, 08:26

Andy - have you replaced/ruled out the cables? These replaced/ruled out the cables? are often the problem with stiffness. I assume you have also loosened the tensioned/resistance screw? If its the control boxes then a good clean and regrease would be a good start.

9D280 · 06 October 2009, 13:22

I'll second that.

Also if you find that there is a lot of slack in the lever wrt the response of the engine, the mechanism inside is full of plastic bushes. It;s a wonderful mechanism until some slack gets into the pivots, then it all goes pear shaped. From memory I either paid £5 or £15 for a full set, and now I have fingetip light control and instant throttle response.

The BIG thing is when splitting the boxes be very careful - the alloy the casings are made of is very brittle, and reacts nicely with the stainless fasteners. And that's the voice of experience........

Andy Young2 · 06 October 2009, 13:48

Polwart - I shall investigate cables and see if they are moving freely. I can then look at lubricating them as well. Thank you for this advice

9D280 - I shall also have a look inside the control boxes taking care when splitting them. I shall look at bushes etc and give the box a clean and regrease. By the way do you remember where you got the plastic bushes - were they a service kit from a dealer?

I will report back on progress. Many thanks

Daniel · 06 October 2009, 13:58

I too have rebuilt a few 703 control boxes.

As someone already said, the casing is brittle, and the bushes wear. I got them thorugh a Yam agent and replaced. I also recal it's a special greece used but cant recall prehaps someone else can comment?

Also i recall the wiring is a pig to fit back in, but that comment probably wont help you much.

9D280 · 06 October 2009, 14:40

I phoned the local Yam dealer and asked for "all the plastic bushes in a 703"! No idea if there's an official kit or not.

I just used Yamlube 'coz I had it to hand. A year on it still hasn't gunked up.......

Oh, yeah, and my wiring is now i nthe console! (with an umbillical to the ASIG switch)

Daniel · 06 October 2009, 16:16

Quote:

Originally Posted by 9D280

Oh, yeah, and my wiring is now i nthe console! (with an umbillical to the ASIG switch)

jyasaki · 06 October 2009, 16:38

Clunk on engaging drive may be due to running a heavy prop. Might try it with no prop installed and see if that makes a difference.

My F115 has a pretty heavy thump when engaging the gear at idle (stainless prop - it's still there, but lighter with an aluminum prop.) As far as I know it's fairly normal.

jky

Andy Young2 · 07 October 2009, 04:32

Daniel - thanks for that I shall try local Yam agent and see what he has.

9D280 - I like the sound of the bail out plan wiring in console and shall keep that in mind

jyasaki - thanks for the tip; I am running ali props but shall try engaging gear without prop. Having received advice here I think 'clunk' may be linked to cables, adjustments etc

Does anyone have an exploded diagram of 703 control box they can post. It may be useful to order parts from and to help me get the thing back together properly

many thanks