Can't remember how it fits back together...

[tr7dan]

I dismantled my carb assembly about 20 years ago and now am at the stage where I have the time to get the car back on the road but can't remember how the linkages etc. fit back together. First problem is that the throttle actuating arm 'hits' against the manifold before the carb butterfly is fully open - I can't see any other way that the mounting bracket/linkage fits to the manifold other than just the two bolts so it can't really be fitted in the wrong place. The bracket is not particularly distorted - is this a common problem and how is it overcome ?

Picture is viewed from under the manifold assembly with carbs etc. removed

https://youtu.be/5Mvm1n-HLtw

[dursleyman]

See the pic below.

[dursleyman]

Does this picture help?

[tr7dan]

Hi Russ

yep, that's the same as mine - I've put a red arrow on your picture to show where the arm hits the manifold when the throttle is opened - as in the video clip I posted

[saabfast]

The arm arrowed does not turn the throttle spindle. There is a connecting rod attached to the arm as shown in Russ' photos which turns the throttle spindles. On the parts one I have in the garage the arm shown does not travel as far as the manifold in operating the throttles.

[Beans]

First check the throttle link between the carburettors is fitted correctly.
Also bear in mind that the lever should rest against the stop of the linkage mechanism in the idle position.
If that proves OK, try adjusting the throttle cable and link between the two carburettors with throttle wide open.

[tr7dan]

I've had to put two washers between the linkage mechanism bracket and the inlet manifold to space it slightly to clear otherwise the actuating arm fouls the manifold on full throttle no matter how I position or adjust it.

One thing I have noticed though is that the combined spring power of the two carb link rod springs and the spring on the actuating arm is quite strong..... does it really need the additional throttle return spring 159463 ? ... or does this put excessive strain on the throttle cable, which I know is prone to breakage ?

[Beans]

... does it really need the additional throttle return spring 159463 ? ...

If the movement is excessively heavy, check the throttle cable and lubricate it if necessary.And check for broken strands on the cable.
Another culprit is the alloy link rod that will wear. I changed that for a ball jointed rod many years ago.



So no more problems with a heavy throttle. Though the lever arm angle of the link rod is far from ideal.
As a result the first part of the throttle pedal's travel will always be a tat heavy. Not ideal for gentle cruizzzing

[Graham.Fountain]

I know that when that linkage carrier plate goes on a Sprint manifold, it needs a spacer between it and the manifold. Are you sure the TR7 manifold doesn't take one too?

Graham


P.S. Found this image in my files, which is a bit off, cos those are HS8s on a Sprint maifold. But if I didn't get that spacer off a TR7 with the linkage plate, I have no idea where it came from.

G

[tr7dan]

I know that when that linkage carrier plate goes on a Sprint manifold, it needs a spacer between it and the manifold. Are you sure the TR7 manifold doesn't take one too?

thanks Graham...
no sign of a spacer in the parts book so I guess not

cheers

Dan

[Graham.Fountain]

No, I can't find it in any parts lists, but I know I have had several, and it's not from between the Sprint link plate - the one with the wiered cam and roller - and manifold. I'll need one later when I start to re-build the TR7 Sprint carb set. I'm at the garage tomorrow where I have a 78 y.m. TR7 engine that I don't think has been mucked with. So I'll look if that has one.

Graham

[Graham.Fountain]

Took a while to get a round tuit, but I had a look at the TR7 set and it ain't there either. Does anybody have any idea where this spacer might come from?

Graham

[dursleyman]

Graham, not quite sure what link plate you are referring to so is it the one on this standard set of TR7 carbs?
Rimmers list it as a Linkage Plate part no. TKC1718

[Graham.Fountain]

No, I mean UKC5851. It was fitted to the Sprint manifold in the TR7 Sprint, with a different throtle lever bar, like UKC6848, but longer to account for the different width between the carbs - easy enough to make from a TR7 lever and a Sprint choke bar/spindle. I think that had this spacer between the plate and the manifold.

I've used one of these spacers in the set in the picture, because I used the TR7 throttle plate between the HS8s. But I though I had more than one and didn't think it was one of the half dozen parts special to TR7 Sprint, like the lever bar, etc., but maybe it is.

Graham

[trsforever]

Hi, have you found a cure to this problem yet?
I have watched your you tube post and there are no carbs or linkage fitted when it is all assembled it should clear by about 4-5mm that arm wont actually go that far that it hits the manifold as the throttle shaft hits the stops on the carbs first. Good luck.