Dual Quad Problem

[wtm442]

Make sure that the linkage is not binding. Spray some penetrating oil on every joint and see what happens. You may also need a stiffer return spring.

[undy]

Originally Posted by wtm442

Make sure that the linkage is not binding. Spray some penetrating oil on every joint and see what happens. You may also need a stiffer return spring.

I'm thinking linkage/gas pedal problem too.. If it's cable operated, check for frayed cable (could be hanging up internally in the housing). It's happened, with like symptoms, to me too.

Dave

[RICK LAKE]

ERA Chas Does this happen when the motor is hot or cold? If cold you should be able to seperate and check all the pivot points one by one. Make sure the pivot center piece is free and moving easy, If you feel any binding replace that joint. What I used for linkage lube is chain lube for a motorcycle. It's waterproof and stays where you spray it. 15 years out of this setup is a long time and you got your mileage out of it. I would next check the hiem joints on the bars for the car linkage to make sure they are free too. It could be the gas pedal pivot heim joints. After this you are looking at the carbs, the first thing to check is the choke high ilde plate and that it moves free and doesn't stick. I have had a couple of carbs with chokes,( 600, 780 ) that this plate wears on the shaft and hangs up, some times hot other times cold. If you get the car to act up, turn off the motor and pull over to the side of the road and look at what is not in the right postion on the carbs. DON'T touch anything right off, just LOOK. If you don't see anything then start to move the linkage and see if anything changes. Next would be the carbs themselves, Check shaft end play and wobble. If you are running strong return springs to the main linkage arm you will wear out the throttle shafts and base plate unless they are roller bearing. I don't think you would have this done unless racing. You would have to check to see if there is even bronze bushings the shafts ride on. If not Send out both base plates and have thing done. You will not always feel a shaft hanging up unless you move it to the stop and feel a small jump. If it is a vacuum leak coming from the motor, I have found that using a small bottle of propane with a little vacuum hose and needle point end under LOW pressure will help you fine and external leaks.If there is an external leak the motor will pick up rpm's. The intake gasket could also be split and leaken after 15 years of running. I have seen a few #1020 felpro gaskets split and leak. If you want to talk about this some more , call me 732-254-3536 in the evening est time Rick L.

[jhv48]

Before you get too deep into this, check one very simple thing:

With the engine fully warm and parked, disconnect the linkage and throttle cable and manually rev the engine (at the carb) to about 2500 RPM and then VERY SLOWLY let the carb linkage return to idle.

I'm betting the carb will not return to idle but will hang up somewhere.

If it does, BY HAND, grasp the throttle linkage at the carb and see if you can manually close the throttle. AT THE CARB!

If you can close the throttle so the car returns to normal idle, you have narrowed down the problem to the throttle shaft or maybe some deposits are preventing the butterflies from completely closing, thus binding slightly.

If this happens, take the carb off and turn it uside down. Now look through the bore and shine a flashlight in the bore from the opposite side. Manually open and close the butterflies and look for even light around the entire throttle plate. If a dark spot appears, it means it is hitting the bore and could be slightly binding at that point. Sometimes a simple adjustment is all that is needed. Possibly needs cleaning too. Either are very easy to do.

Good luck.