1972 Float Adjustment ...

[Mark Maras]

 He may have changed the pivot points but that doesn't guarantee the float level is correct. Why does he have the front carb mixture screw one full turn richer than the rear carb if the float level is correct in both. Well anyway, when he's done playing with the carbs, and hopefully it's running to your satisfaction, I still strongly suggest that you grab a screw driver, pull the chambers and pistons and verify that the float levels are correct. Remember, your goal is 2 1/2 turns down on both carbs with the fuel level (determined by the float level adjustment) just below the tops of the nozzles.

[jalexquijano]

1 hour ago, Mark Maras said:

 He may have changed the pivot points but that doesn't guarantee the float level is correct. Why does he have the front carb mixture screw one full turn richer than the rear carb if the float level is correct in both. Well anyway, when he's done playing with the carbs, and hopefully it's running to your satisfaction, I still strongly suggest that you grab a screw driver, pull the chambers and pistons and verify that the float levels are correct. Remember, your goal is 2 1/2 turns down on both carbs with the fuel level (determined by the float level adjustment) just below the tops of the nozzles.

So it should not be more than 2.5 turns clockwise each?

On 8/2/2018 at 9:52 AM, Mark Maras said:

 Yup, just remove either the 3 or 4 screws, remove the suction chamber and piston. According to Bruce Palmer (ZTherapy) with the mixture screws 2 1/2 turns down. the fuel level should be 1/16" below the top of the nozzle. It's an easy way to verify the float levels are right.

Well my mechanic drilled a hole on the ears of the front carburetor float lid in order to get the same level on both carbs. We will test the car tomorrow in traffic to see of it still dies at idle. My problem has always been at idle.

[Mark Maras]

If the float levels are correct, 2 1/2 turns down will be close. Getting the float (fuel) levels properly set is the primary mixture adjustment. The mixture screws are the fine tune adjusters.

[siteunseen]

When the carbs are right it's like a new car.  I drove mine yesterday, bogged it down in third gear and gave it some gas.  Away I went, can't make it stumble and I try.

[siteunseen]

Mark, I mentioned to Jalex  a few years ago what Steve says in the Just SUs DVD.  They're shipped dry, no resistance in the float chamber to slow the float against banging around during shipping.  You have his respect, I don't,  maybe he'll listen and verify the floats setting.  Good luck.

[jalexquijano]

Well i tested the car today with the front carb adjusted to 4 turns clocks and the rear carb to 2.5 turns. Mechanic considers that the fact that the depht of the hole where the needle valve seats in comparison to the depth of the hole of the other needle valve fastened in the rear carb is why he had to drill the additional hole on the lid to insert the pin and adjust the front carb to 4 turns. Anyway i was thinking that since i have another carb set i could also replace the rear lid of the other carb to see if i could then dial both carbs to 2.5 turns and then the car should have no stalling issues at idle. The only way he could have the same fuel level on both carbs is through this adjustment.

Edited February 10, 2018 by jalexquijano

[Mark Maras]

 I understand the reasoning for moving the pivot holes. I believe Cliff shimmed a needle and seat to move it down. Keep in mind that they did work with unequal lengths from the factory and they had a reason for doing it, the reason escapes me right now. I believe it was G forces. BUT, as I stated before, the mixture adjustment screws are FINE TUNE ADJUSTMENTS ONLY. The primary mixture adjustment is the float (fuel) level adjustment. Until the float level is very close to the proper setting, the fine tune adjustments (mixture screw) are not going to compensate for float levels that are too high or low. Pull the damned tops off the carbs and tell me where the fuel level is in relation to the tops of the nozzles at 2 1/2 turns down. Until we get that settled, all else is uninformed guess work.

[jalexquijano]

Pictures of plugs 1 2 3 4 5 6 

[jalexquijano]

I crank the car again and i did notice some sputtering and hesitation while driving between 3000 to 4000 rpm. Ill check my fuel pump pressure tomorrow hoping the mechanic did not left the pump running without cranking the engine for long time.

[Mark Maras]

 Jalex, Look at post #s 33, 35, 37 and, especially #43 again.

[Mark Maras]

 BTW, I see no reason to check the fuel pressure based on the symptoms you've described.

[jalexquijano]

I had these symptoms before and it was ny airtex 8012s electric fuel pump going south.