[jimmy wayne]

hey guys, i just set the timing in my 1970 302 auto, an for some reason i can take the idle screw competely of the carb and it stays running, i can mess with the timing to bring down the idle but then it makes the car run like crap, when i put the car in gear it bangs realy hard , the carb is the holley 4160, timing is set at 6* btdc, please help thanks

[matches3red]

have you rebuilt the carb?
it could be alot of things..

[jimmy wayne]

please only respond if you what you are talking about,if you own a 1980 mustang with a 4-cylinder,stay out of the classic page please,
i am looking for answers , not questions

[Mn66emberglo]

Jimmy Wayne with answers like that YOU are not going to get a lot of help in this forum. The guy with the 80 mustang is right. It could be a lot of things. Have your rebuilt the carb? Yes and we could go down a list of items that mostly would involve vacuum leaks and check those out. No and I would look at your choke adjustment. If the choke is set too lean then it is tough to get the throttle adjustment down to the correct idle when the timing is set. Also if the choke plate is not adjusted to the correct clearance on full choke that can cause an issue. Get your specs out for the 4160 and start on a complete tuneup NOT just the tiiming.

[The Greek]

You need to get the primary throttle plates back down into the idle transition slot to bring the idle circuit back into operation. You will need to close the primaries and open the secondaries a bit to allow the same amount of air into the engine. There is a screw adjustment for opening the secondaries, it's in the base plate.

To do this you'll need to pull the carb. to access the sec. adjustment screw. Since you'll have the carb off, look into the prim. venturi at the bottom there is a vertical slot. This is the idle transition slot. The prim. throttle plate needs to cover a portion of it. Use the idle speed screw to adjust it down.

You should now be able to adjust the idle mixture, but you will still need to balance the amount of air into the engine by opening the secondaries.

Set the carb up like this: Close the prim. plates until about .044-.060" of the transition slot shows from the bottom side. Open the secondaries up by turning the adjustment screw clockwise 1 1/2 turns.

If this still doesn't get the idle adj. screws to working, you will need to drill holes into the prim. throttle plates. That's a whole other story.

[matches3red]

i dont have a 4cyl.
i have worked on carbs for awhile man.
theyre a pain, thanks alot though