70 roadrunner surges and hesitation

[SlinktRR]

Lean surge means you need more fuel. Pop the metering rods and springs out of the eddy and post what you have, the springs will be color coded and the rods will have a 4 digit code stamped on them.

 

[BL1 70 RR]

If it turns out being your pistons I would try and take it to the guy who rebuilt it and have him do it at a discount for messing it up the first time.

 

[BL1 70 RR]

My carb is running 7547 Rods and silver springs

 

[SlinktRR]

Look at pg 12 in your carburetor owners manual it will give you the calibration chart for the 1406. Looks you have factory stock settings (8" springs, 0.098" main jets, 0.095" secondary jets, 7547 rods). Check your idle vacuum, if you are below 10" vacuum then you will want to put something like a 5" spring (orange) in. Look at the calibration chart for the 1406 and try jet/rod combinations in the top right quadrant of the chart (like 23 or 19). This will richen both cruise and power modes.

You will need a calibration kit for your carb to do this. If you plan on keeping edelbrocks then this is a good investment as you will be able to tune the carb properly for your application. You can also buy individual rods, jets and springs.

 

[BL1 70 RR]

I'll pick a kit up this weekend and start to play around with it!

 

[wsutard]

So my mechanic figured out my surge/buck issue. Turned out the distributor had prematurely worn down and was just a tad lose and wobbly which was causing timing and fire issues.

Replaced the distributor, runs great now.

Go wiggle yours, see if there is some play.

 

[BL1 70 RR]

I checked and mine has some play, I'm going to order a new one and see if it helps!