On my 1970 series 2 with the accelerator pedal fully depressed the Stromberg carb butterfly valves are not fully open. I presume that if the linkage was working correctly the butterfly valves should be fully open. I would say the levers on the carbs are about 1/2 ins off the stops.
The accelerator linkage is complicated to say the least and there is quite a bit of free play in it. Can anyone give any advice on where most of the free play is and how to reduce it?. For instance can the connecting rod, 25, that runs across the fire wall be adjusted in length or the actuating arm coming out of the pedal box, 10, be re-positioned ? None of the other linkage parts seem to be adjustable.
Both 17 and 25 are adjustable for length. The arm (10) fits in a slot in 3 so is not adjustable. Just be sure you don’t lengthen them too much or you won’t be able to get a good idle/fully closed throttle butterflies.
One thing that you may not have noticed is that the holes in item #21 (standoffs) are not concentric with the outside diameter. So, you can loosen the bolt and rotate the standoffs to change the stops at either end of the linkage travel.
And one more thing, if there seems to be a lot of free play on the pedal before the linkage moves, the biggest effect on adjustment can be made on the vertical shaft near the pedal box. Item 17 I think without my reading glasses
I started at the carbs and worked my way one by one to the gas pedal taking out the slack. Most of mine was at the item 40 bushing mentioned above but also at the linkage point for the two carbs. Best thing I could think of there was a cut off split pin in that slot to take up all the slack there.
If your secondary butterflies are still in, there may be a timing problem with them. The are directly linked to the carb butterflies and can keep them from opening fully. The linkage in not adjustable either. See:
