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Series D throttle cable /junction box


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Non-VOC Member
I' m trying to fit a junction box for the throttle cables on my open series D Rapide fitted with monoblocs.
It's the plated one from the Spares co.
My problem is that I can't get full throttle ie the cut away on the slides go flush with the carb bodies leaving the rear of the slides about half way open and this appears to be because the brass slide in the junction box is hitting the end of the box and limiting the travel.
Clearly I' m missing something but I' m stumped.
If anyone has fitted one of these,I'd appreciate some detailed advice . I don't want to fit a twin pull system.
I notice that the Spares Co. also have fittings to give a smooth right angle curve for cable entry to the carbs. Has anyone fitted these to a D ?

Thanks Mac


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VOC Member
The way I would go about this is to first of all measure the total movement possible with the junction box when nothing is connected to it. Then I would measure how much cable travel is required to move the carb throttle from fully shut to fully open. Provided that the junction box movement equals, or preferably exceeds, the movement required at the carbs then it should be possible to make everything work. If all seems to be well with the range on the various items then it can only mean that the cable adjustment into the junction box or that between the junction box and the carbs is incorrect. For example, when the throttle is fully closed is the slider in the junction box at the lower end of it's travel?

Gerry Clarke

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VOC Member
Had a similar issue with my C Rapide using standard carbs. plus an old brass junction box. When I first got the bike, the slides would only retract half way. Had to take the carbs. off and make up new cables on the bench. I used the original junction box - nothing wrong with it. Part of the problem had been soldered cable ends standing proud of the nipple holder and preventing full travel within the sleeve of the junction box. The nipple ends must sit fully within the recesses of the holder. Making up new cables like this, with the carbs. and throttle on the bench, allows you to easily see the slides synchronized. I also used this opportunity to remove the chokes and choke cables. They contributed nothing to the starting procedure, on my bike at any rate, and allow the thottle cables an easier life when it comes to routing under the tank. (I would guess that new throttle cables from the spares company would be correct, but I have not used them myself.)



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Non-VOC Member
Learning to make your own cables is a must my book and the cables themselves from industrial suppliers , stronger,thinner wire used to wrap a certain size cable is soooo flexible.... delightful. If I continue i'll get back to aircraft again to the horror of all.
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