Chris Bracey Posted May 12, 2019 Report Share Posted May 12, 2019 Does anyone know why there are two springs on the 1979 spitfire 1500, each carb has a spring but there is also strong spring from the link to a bracket on the suspension turret. Is this a form of "pressure back" to inctrease economy. Its so stiff the strottle has a pressure point to overcome at the start of throttle travel. I think the spring is too strong.? Link to comment Share on other sites More sharing options...
Anglefire Posted May 12, 2019 Report Share Posted May 12, 2019 Are you sure its a standard fitment? My 77 doesn't have one, it relies on the ones on the carbs alone. Link to comment Share on other sites More sharing options...
johny Posted May 12, 2019 Report Share Posted May 12, 2019 I fitted an extra spring to my Vitesse carb operating arm because I found the existing set up too light for my heavy right foot but years later believe the side loading it gave has greatly accelerated the spindle wear on the rear carb😖 Link to comment Share on other sites More sharing options...
NonMember Posted May 13, 2019 Report Share Posted May 13, 2019 I'm pretty sure all of my Triumphs have had a second spring. Certainly both Vitesses did (one an early rod-and-arm linkage, the other a cable) and the pedal is ridiculously light without it. I think the Dolomite 1500 had two return springs on the intermediate linkage between the cable and the throttle shaft, as well as the one on each carb. In part, I think it was done as a safety measure. Springs can break or fall off. If you only have one throttle return spring, and it breaks, then your throttle sticks open. If you have a second return spring then losing one of them only makes the pedal very light. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 13, 2019 Report Share Posted May 13, 2019 Cables are not the best used , the way forward it to go to your local bikenshop and get some bike brake cables These normally have a derin liner and a long cable will make two throttle cables You need to get the right fixed nipple and a solderless one to fit on the cut end Advantage is very cheap , better and you get two out of one length. Most spits have a twin spring , its designed to wear out the throttle spindles, the return spring needs to be on the pedal operation Rather than the carbs. Which have their own hair spring to return the throttle plates You need to keep tension in the cable so if the clip flies of you dont let the nipple pop off the back of the organ pedal Pete Link to comment Share on other sites More sharing options...
johny Posted May 13, 2019 Report Share Posted May 13, 2019 There's already one spring on my throttle pedal and I've always meant to see if I can squeeze in a second one although now I've got used to the light standard set up.... Link to comment Share on other sites More sharing options...
Clive Posted May 13, 2019 Report Share Posted May 13, 2019 Swap the sting spring for a lighter version. I have used the STD carb springs, it helps the feel. Re cables, took a bit of searching but I found polished inner bike cables and PTFE lined outer. Used with solder less nipples it makes an ultra smooth cable, much much better than off the shelf items. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 13, 2019 Report Share Posted May 13, 2019 6 hours ago, Pete Lewis said: You need to keep tension in the cable so if the clip flies of you dont let the nipple pop off the back of the organ pedal Pete Used to do that in Minis when I fitted new accelerator cables; they always jumped off the pedal and left me with no power, usually when needed! Link to comment Share on other sites More sharing options...
Chris Bracey Posted May 14, 2019 Author Report Share Posted May 14, 2019 On 13/05/2019 at 08:10, NonMember said: I'm pretty sure all of my Triumphs have had a second spring. Certainly both Vitesses did (one an early rod-and-arm linkage, the other a cable) and the pedal is ridiculously light without it. I think the Dolomite 1500 had two return springs on the intermediate linkage between the cable and the throttle shaft, as well as the one on each carb. In part, I think it was done as a safety measure. Springs can break or fall off. If you only have one throttle return spring, and it breaks, then your throttle sticks open. If you have a second return spring then losing one of them only makes the pedal very light. Link to comment Share on other sites More sharing options...
Chris Bracey Posted May 14, 2019 Author Report Share Posted May 14, 2019 Just now, Chris Bracey said: Hi. I looked at leatherhead. It seems a fit on the 1979 although i know the car was built in 1978. I will stretch the spring or heat it to soften the tension. Right now its too tight and needs a reaĺy hard puch to get it started. I like a light throttle so mighttry with it off for a while. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 15, 2019 Report Share Posted May 15, 2019 Springs dont cause sticktion your problem is more likley to be a cable problem Worn outers and snagged inners need a high load to overcome initial movements removing or lightening the spring load just allows a poor cable to work a bit better...for a while The double spring arrangement was used for a good few years on twin Su spits . Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 15, 2019 Report Share Posted May 15, 2019 12 hours ago, Chris Bracey said: Right now its too tight and needs a reaĺy hard puch to get it started. I like a light throttle so mighttry with it off for a while. I had that on my Mk3 GT6 way back, and it was worn bushes in the linkage mechanism, not the springs or cables. It used to be hard to push down, then suddenly it would surge forward and make the car jump. Check to see if yours has any movement that it shouldn't. 1 Link to comment Share on other sites More sharing options...
Chris Bracey Posted May 19, 2019 Author Report Share Posted May 19, 2019 Thank you all for the input. I will investigate the options. Good idea for the bike cable . Really helpful all . Link to comment Share on other sites More sharing options...
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