Carburettor throttle return spring anchor point

[Nick Whitehead]

Hi,

On my Vitesse 2L MK2, the throttle return spring is attached from the lever on the carb (150 CD's) via a bit of wire with a loop in the end to a hook which is hooked onto the chassis. There does not seem to be a proper anchor point?

The spring passes very close to the solenoid delivering power to the starter motor with exposed terminals threatening to short out.

What's the correct way to anchor it? Like this (seems odd)? Or some other way.

Thanks for your advise and guidance.

Nick

[Colin Lindsay]

That sounds the same as the early GT6; in mine it actually rubbed off the steering column.

I think to get round this, the initial section from the chassis up was an 'S' shaped metal hook, which was thinner than a spring, and so any required spring could be shorter and well above any working parts.

[Aitch]

I have a 1979 Spitfire, and I think the set up is very similar with the return spring.

Looking at the picture you can see the return spring attachment to the carb linkage. The other picture, if you look at the BL Cars air filter, below the centre nut is a very short end of the return spring where it attaches to the hole in the frame work. It appears to be a normal fitting place as the manuals I have don't show the exact location. Hope this helps,

Aitch 

[johny]

Ha, just put one on my MK1 Vitesse and Ive hooked it into the vent slot of the side valance.

However theres a bit of history to this as I dont think the car came with one as standard cos if I remember correctly when I got it in 88 it didnt have one and I found the throttle pedal too light so added it. Fast forward 30 years (>40k miles) and I found my carb spindles (particuarly the rear) heavily worn which I put down to the tension from the added spring. I replaced spindles and removed the spring all ok but just recently the carb butterflies have stopped closing properly when running even though they snap shut perfectly with engine off. Ive tried everything but have had to resort to putting the spring back on which presumably will slowly wear the spindles/carb body again☹️

[Colin Lindsay]

Gt6 parts diagram on left, Vitesse on right. Seems to be roughly the same setup, except that the spring hooks to a different place at the carbs. On some models the long metal hook hooks onto the flange at the edge of the sump.

  

 

[johny]

This is the diagram from Canley and it makes interesting reading but unfortunately doesnt say where it hooks: 

[trigolf]

On my Vit Mk 2 it has always been hooked into the side valance louvere. I

 

 

[johny]

Its strange as the cylindrical springs on the carbs should take care of closing the butterflies but obviously Triumph found there was a need for additional force although as I say it will put side thrust on the carb spindle...

[Iain T]

My MK2 has stainless steel heat shields fitted to the carbs so I drilled a hole in the rear one and fitted a spring from there to the throttle spindle bracket. Works a treat. 

Iain 

[Peter Truman]

I know my Mk2 V is all original owning the car for 52 of its 54 years, the spring extension rod item 26 has a kink in it with hooks at both ends, it goes between the starter and engine block and the bottom hook anchors on the sump lip, it clears all the starter electrical connections even the retro fitted Hi Torq starter, but it can be a bug*er to clip over & fit over the sump lip.

Photo can be supplied later today, I'll even unclip the extension rod 26 to show the Z kink/bends at its top, which I assumed were to be able to adjust the spring tension more pronounced.

[johny]

Makes sense to go on the sump as then it all moves as one with the engine but its such a long way down😒

[68vitesse]

On my  Vitesse Mk1 2L spring and extension hook to hole in top flange of engine side valance.

Regards

Paul

[Peter Truman]

Johny the promised photo of my believed original Mk2 Throttle Spring Arrangement anchoring under sump lip, just been out to the garage uncovered blankets off the car and took photo it's 6:30PM here & ga*d its cold out there only 11C!

[Iain T]

This is my system

 

[johny]

Thanks, yes it sounds like Triumph were messing about with different arrangements back in the day. Think I'll keep mine but look for a weaker spring to minimise the problems I had before....

[Colin Lindsay]

Someone did the same on my 13/60, hooked to the nut on the rocker cover. No idea why, I removed it and the car has run very well without.

[NonMember]

25 minutes ago, johny said:

Think I'll keep mine but look for a weaker spring to minimise the problems I had before....

If you have an arrangement like Colin's photo, where the throttle cable and the spring operate at opposite ends of the spindle, then I'd expect added wear. If it's like Iain's, where the spring operates directly on and in line with the cable, then it shouldn't significantly increase any lateral loads on the spindle.

[Peter Truman]

Mine is the same as Iain’s off the same throttle lever straight down & behind the starter motor.

[johny]

Think there must be a downward pull on the spindle from the spring especially when the butterfly is fully closed and this is the point at which wear might occur.... 

[Iain T]

2 hours ago, NonMember said:

If it's like Iain's, where the spring operates directly on and in line with the cable, then it shouldn't significantly increase any lateral loads on the spindle

Blimey I've done something right! I would say by design but it reality it was the easiest solution. Without the spring when decelerating to idle the revs would bounce about a bit before settling down. 

Iain 

[Iain T]

2 hours ago, johny said:

Think there must be a downward pull on the spindle from the spring especially when the butterfly is fully closed and this is the point at which wear might occur.... 

It must be minimal but as I've had spindle bushes and seals fitted I'm hoping it will never be my problem.....