View Full Version : TR6 TR6 accellerator linkage does not

06-04-2011, 02:54 PM
I am getting the old girl slowly back together. After the accelerator linkage was connected, I noticed when the pedal was fully depressed, the carbs were not fully open. At first I thought it was the gas pedal not being set properly, but it turns out to be that the spring on the linkage between the carb and gas pedal rod compresses to a point that prevents further opening of the throttle valves.

Any thoughts on if this is by design, or do I need to give the interconnecting linkage (Item 30) more length by extending the rod end further out?


06-04-2011, 03:08 PM
It's designed to work if you get the lengths AND pedal height adjusted.
I don't see in that illustration is the "fork" that makes the spring compress when you accelerate. Not that it has anything to do with getting WOT.

06-04-2011, 03:36 PM
That's the one I have. At the carbs, when I attempt to manually open the throttle, the spring fully compresses so I guess I need to back off on the end piece to give me more movement.

That will also put the accelerator pedal a bit outward from the brake pedal.

Time to ignore some more stuff in the Bentley book, particularly as it relates to the length of the linkage.


06-04-2011, 04:08 PM
That's what the Ratco is all about. Complete opening throttles

06-04-2011, 07:30 PM
Which it does, very well.

AND, you can adjust your pedal height to be whatever you want it to be with very little hassle.

06-04-2011, 10:15 PM
You've got to admit, though, that it's not as easy as it sounds, installing one of those Ratco cables.
In fact it might be a little more difficult setting up the Ratco to assure WOT.
The only real advantage I've noticed is a smoother pedal action by reducing 3 ball and socket joints down to just 1 and eliminating that pivoting bell crank.

06-05-2011, 08:48 AM
Having gone back and looked at my installation, and then having slept on the issue, I am convinced that the fact that WOT is not reached because of the spring on the linkage had to be known to the engineers. Even with out the spring, there is not enough throttle pedal movement to fully open the throttles. So, that being true, it implies the engineers installed more carburetor on the stock engine then it needed or could handle, or for some other reason, by design prevented you from opening the throttle that additional 10% or so.

In my mind I can support this conclusion recalling several conversations about triple carb performance over the stock set up, where some people here and on other forums indicated little, if any noticeable performance improvement having three rather then just two carburetors (or maybe it was the hassle factor with the triple setup). I also remember that when this car was on the road, red-line and above, to near 6,000 rpm could be attained.

But then I could be wrong.

So for now, I am going to stay with the stock configuration and see how it goes when in a couple of months (hopefully), I'll be back on the road.

Thanks for your input

06-05-2011, 10:19 AM
It is possible. When I still had twin carbs on my TR6 I was able to get full throttle opening by following the exact instructions in the Bentley. It did raise the gas pedal but I was able to readjust the pedal without altering the linkage, and adjusted the throttle stop on the firewall.

06-05-2011, 10:27 AM
I'm a guy who has triples with a Ratco cable and I will say that triples on a stock engine isn't practical. You have to adjust the B1AF needles pretty low to avoid an over rich mixture with triples and that's with modest engine mods.
But I had a stock 74 with dualZS and the kind of a carb linkage you are fooling with for about 5 years and I can tell you that it is possible to have the throttle disc fully opened with the stock linkage.
Loosen the vertical link from the interconnected throttle shafts, By hand, manipulate the throttle shafts to WOT and wire or wedge them in place. Put a brick on the accelerator pedal. Then make adjustments in length and height of the linkage components until the socket of the vertical link once again lines up with the ball of the throttle shaft connecting link.

06-05-2011, 11:16 AM
Ok, I'll work on it some more...

06-05-2011, 12:50 PM
Hi Ray - pretty good progress if you are dealing with the accelerator!

06-05-2011, 01:12 PM
Actually, just a diversion as I wait for the weather patterns to get back to normal so I can finish the painting. It is either to cold, to windy, or raining, or health issues (like having my appendix removed at age 64). So until things settle down, I keep myself occupied with the 'little' stuff.

06-05-2011, 02:19 PM
Well it all has to get done right? Progress is progress. Fingers crossed on the weather.

06-05-2011, 08:54 PM
Ken's adjustment technique is spot on. However, I didn't think that installing the Ratco cable was difficult at all.