OK, now that you have succeeded in stoppin’ der floppin’, it’s time for adjustment.

The part of the factory manual dealing with this topic is at the end of Section A, but there are a couple aspects not touched upon in the official publication. The reason given for this adjustment is "to prevent the throttle linkage being strained and the throttle levers working loose." The Book states that the "linkage may be adjusted to allow the toe board to act as a positive stop to the accelerator pedal when the throttles are fully open" but they leave out the fact that only the pedal should be stopping the movement of the linkage, and never the stop tabs on the carburettor shafts impacting on the carb body. In fact, if the carb shaft stops are halting the movement of the linkage, instead of the pedal bottoming on the toe board, the backlash from this abrupt contact can not only strain things but also break the plastic bushing which mounts on the intake manifold and holds the end of the accelerator spindle. If that occurs all acceleration is lost, and you go nowhere until the situation is rectified. This is a more common problem on BJ7’s and 8’s, due to the greater leverage exerted by the longer spindle.

You can go by the factory procedure and adjust according to the book, or incorporate any or all of the tweaks herein discussed. Take a gander at Figure 1, which shows the general overall linkage layout for BJ8’s in the fully OFF (idle) position. My problem with using the BMC method is that the gas pedal is limited to 2.5 inches of travel, which is a little on the short side and leaves the gas pedal set lower than the brake and clutch pedals. I prefer my three pedals pretty much in line with each other, which breaks down to a distance more like 3 inches between the gas pedal and the point where it touches the floor. Whichever dimension you go by, the object is to adjust the various parts of the linkage so that when the gas pedal is buried in the carpet the clearance between the stop tabs on the butterfly shafts and the flats on the bodies of the carburettors is .025" (see Fig. 2). At this position the throttles are fully open, with the butterflies parallel to the carb bores, but because the shaft stop tabs do not contact the carb bodies there is no reverse pressure put on the linkage. Instructions given are based on BJ8 cars, but generally apply to earlier models without going into the finer points like synchronizing tri-carbs.

To adjust for the correct clearance I start at the gas pedal and work up and forward to the carbs. First, align the brake and clutch pedals with each other. On early model cars with the same master cylinder for both brake and clutch the two pedals should be aligned already. On BJ8’s the length of the brake pushrod is set to bring the brake pedal even with the clutch. Then clamp a bar across the brake and clutch pedal arms so it projects over the gas pedal. Referring to the pieces labeled in Fig. 1, slacken the pinch bolt on yoke lever B and remove lower linkage piece C. In the footwell, fix the gas pedal at the desired height off the floor, making sure it is even with or below the other pedals. Prop, clamp, or otherwise hold the gas pedal so it can’t move, then rotate yoke lever B so it’s pointing up and leaning towards the rear of the car at an angle of about 30° from straight upright. Snug the pinch bolt just enough to clamp the yoke without locking it, so the yoke holds the setting but can still be shifted on the pedal shaft.

Next, remove firewall linkage piece E and use a rubber band on cross shaft lever D to hold it firmly up against the bottom of the firewall (Fig. 3). With the gas pedal held in place at the fully up position, set the length of linkage piece C so the yoke lever and cross shaft are exactly connected, with the gas pedal remaining at the desired height, lever D in contact with the firewall, and yoke lever B maintaining the 30° angle. That takes care of the bottom part – now on to the middle. Remove front linkage piece I connecting the spindle front lever to the carb throttle shafts. Adjust the length of linkage piece E so that when it is connected to lever D (resting against the firewall in the OFF position) rear lever F is at an angle of 30° - 40° . Refit linkage piece E. Now for the home stretch. Slacken the pinch bolt on front lever G and stand it straight up, then re-tighten the pinch bolt. Set lever H parallel to lever G and adjust linkage piece I to hold that setting. Lastly, slacken the pinch bolts for the two levers that open the butterflies, located on each end of the shaft between the two carbs (not shown). Swing the two levers around till they are firmly against the fully OFF side of the "lost motion" forks on the carb shafts and tighten them in place. Blip the throttle at lever G and make sure the butterflies return to fully closed when the throttle springs back to the off/idle position.

Now to check everything, and there are two factors to bear in mind. First, you want to be sure nothing can bind or change configuration, and second, you want to have the proper .025" stop clearance at the carbs. In addition, you want to maintain the proper angle on the throttle switch lever. The position of lever D and length of linkage piece E are critical for this. Use a pole, a brick, or a relative to hold the gas pedal buried in the carpet. Check the angle of lever F in this full-on position. UNDER NO CIRCUMSTANCES SHOULD LEVER F BE LESS THAN 20° FROM VERTICAL (Fig. 4). If the lever can travel down any further, as in beyond 5 o’clock, it can flip around and underneath, binding linkage piece E and locking the throttle open. This is not desirable. Lengthen link E as necessary to keep the minimum angle. Then, with the pedal still floored, check for proper .025" clearance at the carbs between the shaft stops and the carb bodies. If the clearance is more than .025" you can decrease by lengthening link I. If, on the other hand, the stop tabs are hitting the bodies you need to adjust for gap. Bear in mind that the angle of F must remain the same and D should stay as high as possible, and that when released to full off the gas pedal should line up at the height you wanted. Therefore it is best to keep E set and shorten link I or, alternatively, shorten C while increasing the angle of B. Sometimes it’s necessary to reset the position of the butterfly levers. You may have to play around a bit before things are entirely to your satisfaction, and if your floors have ever been redone you could be seriously challenged. Should all your efforts to set the proper clearance for the pedal height that you want to use be in vain, don’t lose heart, there is a simple solution. You can always "flat rate" the job by gluing a chunk of paneling or the like to the toe board under the carpet at the point where the pedal comes down, raising the floor to the requisite height for stopping the pedal where it gives the correct clearance at the carbs. Once you have everything where you want it, final torque the pinch bolt for lever B and check the adjustment of the overdrive throttle switch. I find an ohmmeter best for that job.