Best Way To Repair Butterflies

bobscuda67 said
Hey AJ, yes the holes are 1/8 inch in diameter.
My idle speed is 700 rpm in gear and the initial is 14* on a 372 displacement and the cam is a Lunati VooDoo 702 cam. Idles at 19 inches of vacuum.
The idle adjustment screws are 21/2 turns out.

Yes the best way is to replace them but I have been looking and I can't find any. Was going to call Edelbrock tech line to see if there available. If you have seen them let me know where amd Ill buy new ones.
Thanks
Click to expand...
Wait what?...Hang on a sec
...Convertor stall?

Firstly replacing the blades is every bit as much trouble as plugging them. Maybe more.

Is this your cam?
Part Number: 10200702
Previous Part Number: 60402

If yes, then I see that you have traded away Transfer slot exposure to crank out the mixture screws to 2.5T, so you can run 700 in gear with 14* initial while utilizing those big ol' holes.
And I bet you get a big ol' clunk when you put it into gear cuz the no-load idle rpm is 850 or more.And I bet you are having trouble with a tip-in sag.
But the big clue is the 19" of idle vacuum.
So yes, those holes have got to go.
After they are gone, you can up the T-port exposure and return the mixture screws to about 1.5. This will bring the idle speed down and improve both the idle quality and richen up the tip-in, and maybe you can take out some pump-shot.The idle vacuum may not change much. Then maybe you get a lil wiggle room to run a bit more initial, altho with a 372 this is hardly an issue. I would actually be retarding it some more, for a slower idle. But I would run a really early-starting advance curve, so that by the top of the stall speed, it is back to normal..
Now getting back to replacing the blades
No easy task. Those screws are staked in there and possibly loc-tited in. So first you have to completely disassemble the carb more or less to get the baseplate off. Then you have to carefully drill off the staking with a really sharp drill-bit, so you don't have to press hard enough to bend the shaft. Then you have to flip it over and see if the screws will break loose. But the tiniest bit too much force and the screw-head breaks off and then the fun begins. So to prevent that I just heat up the screw heads to start with to relax any locking agent that may have been used. So get this; the torch is already on the bench,lol. Ok so say you get all 4 screws out without breaking any of them. Now you drop the blades out one atta time and swap in the new ones. Then you try and put new cranky tiny PITA screws. Ok so you get them in and snugged down. Now you gave to wiggle and jiggle and pilot theose blades into touching the bores all around, both sides and snug 'em up so they stay put for a bit. Then you check the t-port exposure to be sure they are sortof identical. If they are; then you take out one screw atta time and loc-tite it back in.Now, before the locking agent sets you still want to peen the ends like you found them, so they can no-way-no-how ever drop into the engine.And finally reassemble the carb. Reset the sync. Reset the mixture screws, And put it back on the intake,etc.
Maybe I'm just lazy, but I can drop a "lead ball" in there in a couple of minutes, no disassembly required.