Throttle return spring and Webers

PostPost by: summerinmaine » Fri Feb 18, 2011 1:09 am

I'm mounting the airbox backing plate to the Webers, and the more I stare at the throttle cable tensioner bracket and the throttle return spring, the more I'm convinced that the spring has gotten bolloxed somehow (which is not really possible). The Series 1/2 Manual has a pic that almost, but not quite, shows the proper set up.

Does anyone have a pic of the throttle cable/return spring/tension bracket in situ, so that I can figure out why I'm going whack-o? It's probably just a lack of sleep, but still . . .

Thanks in advance
Jim

Temporarily Elan-less
User avatar
summerinmaine
Fourth Gear
Fourth Gear
 
Posts: 689
Joined: 22 Sep 2003

PostPost by: fatboyoz » Fri Feb 18, 2011 11:12 am

Jim,
I have an S4. Not sure if yours is the same as mine, as the backplates changed at some point. The car is on the hoist at the moment so can't supply a photo.
The return spring has a right angled bend on one end and a hooked bend on the other. With the spring coil pressing up against the rear carbie, insert (from the rear) the hooked end into the small hole adjacent to the cable nipple retainer (part of the back plate). The right angled end of the spring is then inserted (also from the rear) into the small holes adjacent to the ferule that retains the end of the cable (part number 62 from the manual). A bit of a fiddle, but it all manages to stay together.
Colin.


summerinmaine wrote:I'm mounting the airbox backing plate to the Webers, and the more I stare at the throttle cable tensioner bracket and the throttle return spring, the more I'm convinced that the spring has gotten bolloxed somehow (which is not really possible). The Series 1/2 Manual has a pic that almost, but not quite, shows the proper set up.

Does anyone have a pic of the throttle cable/return spring/tension bracket in situ, so that I can figure out why I'm going whack-o? It's probably just a lack of sleep, but still . . .

Thanks in advance
'68 S4 DHC
fatboyoz
Fourth Gear
Fourth Gear
 
Posts: 692
Joined: 04 Oct 2003

PostPost by: types26/36 » Fri Feb 18, 2011 11:26 am

Brian
64 S2 Roadster
72 Sprint FHC
User avatar
types26/36
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3872
Joined: 11 Sep 2003

PostPost by: jimj » Fri Feb 18, 2011 12:06 pm

Yes it`s a fiddly job needing long narrow nosed pliers to poke it through a hole you can`t see without eyeballs on stalks. As the great John Travolta once said; "feel your way "!!
Unlikely, you might think, but the spring can slip off in certain circumstances. It`s only happened once to me but...........you could die, or worse, over-rev. the engine. I`ve attached a crude secondary, emergency spring just in case.
Jim
jimj
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1119
Joined: 25 Feb 2008

PostPost by: Roy Gillett » Fri Feb 18, 2011 3:01 pm

Unlikely, you might think, but the spring can slip off in certain circumstances. It`s only happened once to me but...........you could die, or worse, over-rev. the engine. I`ve attached a crude secondary, emergency spring just in case.


Interesting, Jim. I run Dellortos on my +2 but on two separate occasions I have had MSA scrutineers arguing about the lack of a seond spring on the trottle return. On both occasions the final view has been (after consultation with a higher authority) that Dellortos don't need it but Webers do to pass scrutineering. The suggestion is I think that dellortos have another spring built in but Webers don't and the "Green Book" says there must be a duplicate way of springing the throttles closed.

I haven't checked my facts so should be grateful of any corroboration in case I come across a less flexible scrutineer.

Roy
User avatar
Roy Gillett
Second Gear
Second Gear
 
Posts: 188
Joined: 01 Oct 2003

PostPost by: types26/36 » Fri Feb 18, 2011 4:13 pm

All the Webers & Dellotos I have ever worked on had additional springs AS WELL as the "hairpin spring" that is on the linkage/airbox backing plate, I have seen all sorts of "extra springs" fitted but they generally dont look very nice and in my opinion not required if the original Weber/Delloto spring is in place.
Attachments
DELLOTO SPRING [HDTV (1080)].JPG and
WEBER SPRING [HDTV (1080)].JPG and
Brian
64 S2 Roadster
72 Sprint FHC
User avatar
types26/36
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3872
Joined: 11 Sep 2003

PostPost by: jimj » Fri Feb 18, 2011 4:42 pm

Roy, I think I know which scrutineer you mean??? Given the sort of stuff we do I always think it`s unlikely such an item would result in exclusion in case a refund was requested. See you on the 3 Castles, there`s a cracking Lotus turnout again.
Jim
jimj
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1119
Joined: 25 Feb 2008

PostPost by: summerinmaine » Fri Feb 18, 2011 8:17 pm

Thanks for all the helpful replies and the reference to the images. My "mental image" failed to account for the fact that the shank of the spring would point back toward the engine, as it kept looking to me like the hook was going to foul with the throttle cable. I have in mind to get one of the RDE-type low profile throttle linkage set-ups, but money gets tight as completion nears.

Now if I could just figure out why the back plate-to-carb gasket has openings too small to allow the air horns to fit! :evil:
Jim

Temporarily Elan-less
User avatar
summerinmaine
Fourth Gear
Fourth Gear
 
Posts: 689
Joined: 22 Sep 2003

PostPost by: JJDraper » Fri Feb 18, 2011 8:47 pm

Not really a great help but thought these pics would be interesting.

Common spring failure mode, fatigue fracture on the main winding. Also note from the pic the wear groove on the end that locates on the bracket - one or other of these problems was bound to fail eventually! Moral - fit a rev limiter.

Second pic - the steel barrel that holds the end of the cable is ridiculously expensive from the usual merchants and is occasionally (often) often lost on the move. Keep a spare in the tool bag. I made my spare from one of the metal deelys that come from an Ikea flatpack shelving unit, a hand drill and hacksaw. Not pretty, but cheap - and I know Lotus owners like cheap....

The third pic is a comparison between a 'Lotus' Weber throttle arm and a standard Weber throttle arm. Getting the wrong arm can cause problems with the length of the throttle cable - in case you were wondering the Lotus one is on the left.

Jeremy
Attachments
small spring.jpg and
100_4639.JPG and
short lever.jpg and
User avatar
JJDraper
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1031
Joined: 17 Oct 2004

PostPost by: summerinmaine » Fri Feb 18, 2011 9:46 pm

Very interesting.
Jim

Temporarily Elan-less
User avatar
summerinmaine
Fourth Gear
Fourth Gear
 
Posts: 689
Joined: 22 Sep 2003

PostPost by: cabc26b » Fri Feb 18, 2011 10:47 pm

Jim ,

see below - as attached to a S1 , LHD .

George
Attachments
return=spring.JPG and
cabc26b
Fourth Gear
Fourth Gear
 
Posts: 954
Joined: 21 Sep 2003

PostPost by: summerinmaine » Sat Feb 19, 2011 12:37 am

Thanks George!
Jim

Temporarily Elan-less
User avatar
summerinmaine
Fourth Gear
Fourth Gear
 
Posts: 689
Joined: 22 Sep 2003

PostPost by: Roy Gillett » Sat Feb 19, 2011 10:46 am

jimj wrote:Roy, I think I know which scrutineer you mean??? Given the sort of stuff we do I always think it`s unlikely such an item would result in exclusion in case a refund was requested. See you on the 3 Castles, there`s a cracking Lotus turnout again.
Jim


Hi Jim,

You are right about your scrutineer suspicion 50% but I have also been questioned on a second spring on an MSA event.

You are right about the Lotus entry in the 3 Castles this year. It just gets better and better doesn't it. We must both try to get to the finish this year!!

Roy
User avatar
Roy Gillett
Second Gear
Second Gear
 
Posts: 188
Joined: 01 Oct 2003

PostPost by: rcraven » Sat Feb 19, 2011 10:58 pm

types26/36/74 wrote:All the Webers & Dellotos I have ever worked on had additional springs AS WELL as the "hairpin spring" that is on the linkage/airbox backing plate, I have seen all sorts of "extra springs" fitted but they generally dont look very nice and in my opinion not required if the original Weber/Delloto spring is in place.


It was so long ago that I'm not now sure whether it was on my present Elan with Dellortos or the previous one with Webers, but when the main hairpin spring once came loose the built in additional springs were not sufficient to stop the throttle immediately opening fully and staying open.
Robert
rcraven
Third Gear
Third Gear
 
Posts: 252
Joined: 23 Oct 2007

PostPost by: bast0n » Sun Feb 20, 2011 9:45 am

Having had a return spring snap on me at Castle Combe I have made up my own design of throttle linkage. I posted it last year on Worthwhile engine modifications thread - but if any one is interested please PM me and I will send you the details. It has a very short cable that does not foul the bonnet and two return springs for safety. Smooth does not get close to describing the action....................................but we all say that don't we!

Image

Image
David
bast0n
Third Gear
Third Gear
 
Posts: 312
Joined: 31 Oct 2008
Next

Total Online:

Users browsing this forum: No registered users and 13 guests