Elusive spring
 

There's a spring in my carb that I want to find!

Hey, every site I go to that talks about improving your car's performance seems to mention a spring that's inside a compartment with four screws holding the cover on it. Aparently it controls the secondary plugs, telling them when to fire. I'm told if you cut it down 2/3 or take it out altogether, it'll cause the secondaries to fire around 2000 rpm instead of 4000.
Unfortunately, no one uses the same lingo that the haynes manual uses, so I never know what they're talking about. There are two metal plates on my carb that have four screws holding them on, and both have springs in them. I just don't know which one it is. Can someone snap a picture of it, and post it for me. And.. umm.. could you point it out with your finger or something.. :rolleyes: I'm a visual person, so a picture would really help.

Does anyone know what kind of difference this will make? I have an '83 GSL with a header and one cat (soon to come out). I also have a K&N air filter, so my intake and exhaust isn't bad.. not great but not bad. Has anyone found this helps, or does it seem to make no difference whatsoever?

Thanks.
Clean

You most likely have a 12A so I won't be able to help you. But if you do happen to have an old school 13B, the secondary actuator spring is under a cast aluminum cap held on by 3 screws on the front most part of the carb. It is almost directly below the air filter canister snorkle. Hope that helps.

Speaking of lingo, I always say that the secondaries "open" rather than "fire". It's just details. You're right about cutting the spring 2/3 or completely removing it for more power.

I used to have surging secondaries due to a bad intake manifold gasket (caused by the previous owner's use of a die grinder to remove the old gasket, uhg!). Without a spring installed, it surged really badly (the secondaries would open and close whenever it was floored) so I got one that was already cut and installed it. I later removed it after I installed a good intake manifold. Now my secondaries open quite easily with no more surging! The rest is a long story, but to sum it up, cutting the spring helps, but removing it is a bit better (for the engines I've worked on anyway).

Ok, here's my take on things....

To clear things up, you don't have 'secondary plugs'. You have leading and trailing plugs, one of each for each rotor. The leading fires approx 20 degrees before the trailing, which cleans up the rest of the mixture that hasn't been already burned (more or less). All your plugs fire all the time, you can adjust your timing only by turning the distributor and adjusting the trailing vaccuum pot. But dude really, don't mess with it, trust me.

Alright now, the 'secondaries' you are referring to are your secondary carburator barrels. If you take off your air cleaner, you will see 2 small barrels, the primaries, and 2 larger barrels, the secondaries. Below approx 4000 rpm, your primaries do all the work, to provide for smooth driveability. At high revs, your secondaries open up and allow more air to fuel to be dumped in the motor, which is why you feel a power surge and the exhaust note changes around 4000 rpm.

Your secondaries are vacuum operated. You have a solenoid with a spring inside, when there is enough vacuum to move the spring (ie at high revs), the little arm underneath is actuated and opens the secondary barrels. Now, the resistance of the spring determines how much vacuum is required before the secondaries are opened.

Remove your air cleaner. Stand beside your car on the passengers side. The metal casing with 4 screws on the right side of the carb is the one. Notice how there is a little arm underneath, which opens the secondary barrels. Now carefully remove the cover. Be careful of the gasket, don't break it!!! Now remove the spring and get out your clippers...

Be very careful cutting your spring!!! If you cut it too much, your secondaries will open too soon which feels shitty and uses a shit load of gas. I would recommend cutting no more than 2-3 coils. I cut 2 coils on mine, which feels about right to me.

It makes a *small* difference, basically your power surge comes on a little earlier. So you get a little better power at lower revs. But it's really not any kind of revolutionary mod.

Anyways, hope I've shed a little light on it, enjoy!!

My secondaries come on at real low RPM. It feels like my carb has mechanical secondaries! You just gotta drive it with a little more attention.