Choke pull off

[4ever18]

On 1967, 68 and 69 Pontiac Q-Jets the choke pull offs are the same except for RA engines.  The 70 engine has a pull off that appears identical but I don't think it is.  Can anyone clear this up for me?  Is it just a matter of orifice size or is the diaphragm spring different?
 

[Cliff Ruggles]

67-69 Pontiac carbs used the same pull-off, it's is plastic.

The 1970 non-RA units used a metal pull-off with two fittings.

The currently available plastic ones are WAY too quick on opening rate.  We take each one apart and modify them here.  If you try to use one out of the box the secondaries whip open too quick causing hesitation/stumble/bog that is difficult to tune out.....Cliff

[Kavesh]

Cliff so as long as we get the choke pull off from you, we will be fine as you would have modified them for us? Or am I wrong?

Just getting my ducks in a row with my order from you

[Cliff Ruggles]

We modify all of the plastic ones for the 67-70 engines as they are WAY too quick for opening rate as delivered from the manufacturer.

If you install a pull-off with an near instant opening rate, the secondary flaps will open too quickly and there will be a lean hesitation/stumble/bog.  Tightening the tension spring to try to prevent this will not work, it's ruins the spring.....Cliff

[jamesF]

How do you modify these? I have one on my 67 carb. Do you think I need that tweak?

[Cliff Ruggles]

We modify the new ones because they are way too quick and work poorly.

Some of the older units and most original pull-offs have a restriction built in that delays the opening slightly and may not need any modifications.

We also make adjustable units for folks who want full control, drag race, etc.....Cliff