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Old 15 Oct 2012, 18:55 (Ref:3152461)   #1
Tim Falce
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Weber DCOE Internal return springs.

For the last two races I've been having problems with the throttle sticking open on my triple Weber set-up. The first time was caused by a newish cable somehow twisting inside and jamming the inner cable. I had a similar problem at Snetterton on Saturday but the cables seem fine although one or more of the carbs internal springs have broken.
Does anyone do away with these springs and fit an external one, just like the scroots insist on or should I replace the broken springs? Problem is with three internal springs and three external plus one of the throttle linkage the pedal is very heavy to push down.
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Old 15 Oct 2012, 20:09 (Ref:3152495)   #2
Clive Brown
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I've always discarded the internal return springs on DCOE Webers, on the basis that if they break (and they do) the remnants can jam the throttle.

No need to do this on a DHLA Dell'orto, as the spring is external to the carb body, and broken bits can fall out of the way.
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Old 15 Oct 2012, 22:15 (Ref:3152552)   #3
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I agree with Clive I've always left them out and used external springs.
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Old 17 Oct 2012, 00:08 (Ref:3153122)   #4
tony griffiths
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remove them !
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Old 17 Oct 2012, 18:03 (Ref:3153464)   #5
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I've always thought it best to remove the internal springs, however, I do know of someone who failed scutineering for this at a meeting because the scrut disconnected the external springs and then operated the linkage. Obviously the throttle stayed open, the scrut then failed the car deeming the internal springs/carburettor as faulty and unsafe. I wasn't there at the time so I don't know all the story but I understand the chief scrut backed the scruts decision so my aquaintance had to go borrow some springs off a car from the car park.
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Old 17 Oct 2012, 18:22 (Ref:3153472)   #6
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Probably removed the springs from the throttle linkage. Although the majority are fitted with two springs these do not comply with the blue book requirements as they are not acting directly on the throttle spindle. Answer is to fit two external springs to the end of the spindles. Definately throw away the internal springs as failure usually results in throttle jammed open. Been there got the teeshirt.

Pete Richards
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Old 17 Oct 2012, 18:32 (Ref:3153477)   #7
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I don't see how a scroot can fail on internal springs.
Blue book rule
5.4.2. Be equipped with a positive method of throttle
closing by means of external spring/springs so that in
the event of failure of any part of the throttle linkage the
throttle(s) are sprung closed.
So as long as external spring/springs are fitted there can't be a problem.

I've just removed the offending item and I see It's quite a heavy spring so using only the three external springs I use (4 including the one on the cable itself) will make the throttle pedal quite light.
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Old 18 Oct 2012, 20:55 (Ref:3154052)   #8
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Originally Posted by JasperClan View Post
Probably removed the springs from the throttle linkage. Although the majority are fitted with two springs these do not comply with the blue book requirements as they are not acting directly on the throttle spindle. Answer is to fit two external springs to the end of the spindles. Definately throw away the internal springs as failure usually results in throttle jammed open. Been there got the teeshirt.

Pete Richards
Its 1 external spring per carb, its better if its in built to the linkage, this is what we make, this
is for our 6 cylinder 3 Weber carb motors, but we can sell you just the arm if you like as the arm silver solders to your washer / arm / whatever, the long hole is too stiff, the short hole just right with MGB springs
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Old 20 Oct 2012, 09:45 (Ref:3154754)   #9
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Originally Posted by FastDB2s View Post
Its 1 external spring per carb, its better if its in built to the linkage, this is what we make, this
is for our 6 cylinder 3 Weber carb motors, but we can sell you just the arm if you like as the arm silver solders to your washer / arm / whatever, the long hole is too stiff, the short hole just right with MGB springs
That might be an idea although I wouldn't be happy with a bit that's soldered on.

Those that remove the internal springs to you discard the H collar that holds the top of the spring or leave it in?
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Old 20 Oct 2012, 10:31 (Ref:3154775)   #10
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Originally Posted by Tim Falce View Post
That might be an idea although I wouldn't be happy with a bit that's soldered on.

Those that remove the internal springs to you discard the H collar that holds the top of the spring or leave it in?
They are one piece now if you use the ball joint type that we do, the arm is not soldered on to any other link, it is / was silver sordered one - similar to braze but it flows & joins better, it's the way that most formula one cars were joined when using tube frames - very strong when done properly, all Reynolds 531 tube frame bikes are still made with this.

From Wikipedia' Under Solder
Soldering performed using alloys with melting point above 450 °C (840 °F) is called 'hard soldering', 'silver soldering' or brazing.

Hard solder Hard solders are used for brazing, and melt at higher temperatures. Alloys of copper with either zinc or silver are the most common.

In silversmithing or jewelry making, special hard solders are used that will pass away assay. They contain a high proportion of the metal being soldered and lead is not used in these alloys. These solders vary in hardness, designated as "enameling", "hard", "medium" and "easy". Enameling solder has a high melting point, close to that of the material itself, to prevent the joint desoldering during firing in the enameling process. The remaining solder types are used in decreasing order of hardness during the process of making an item, to prevent a previously soldered seam or joint desoldering while additional sites are soldered. Easy solder is also often used for repair work for the same reason. Flux or rouge is also used to prevent joints from desoldering.

Silver solder is also used in manufacturing to join metal parts that cannot be welded. The alloys used for these purposes contain a high proportion of silver (up to 40%), and may also contain cadmium.'

No silver solder sold in the UK contains cadmium as it got banned, silver solders chemical compounds are altered slightly because of this
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Old 24 Oct 2012, 07:26 (Ref:3156866)   #11
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the genuine weber rebuild kits supply new springs, I use them, they break because they're old and knackered, they wear out and snap at the end were they hook onto the butterfly spindle.

we decided ( on the rollers one time) to only use an 'aesthetically pleasing' external spring to satisfy scrutes, and offer a secondary closure method because a large spring over loads the spindle and pulls on the bearing, and twists the shaft, which alters the butterfly positions, thats sapping power in my book.
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Old 24 Oct 2012, 16:54 (Ref:3157091)   #12
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Originally Posted by zefarelly View Post
we decided ( on the rollers one time) to only use an 'aesthetically pleasing' external spring to satisfy scrutes, and offer a secondary closure method because a large spring over loads the spindle and pulls on the bearing, and twists the shaft, which alters the butterfly positions, thats sapping power in my book.
Which is why our levers / arms only fit on the operating end.
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Old 24 Oct 2012, 22:09 (Ref:3157231)   #13
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which makes perfect sense. and also highlights how crap most of the linkage kits are!
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