having a problem tuning this 340 . Its got 360 j heads,10-5-1 pistons,484 cam ,eddy 600 with air gap intake.

Im a Big block guy, where should the timing be around on a 340? put in as much initial as i can?

Has a huge flat spot off the bottom. Eddy 600's known to have that?

What do you have for vac? What size squiter nozzle does the carb have? Which hole is the rod in on the pump?

going to have to ck vaccum. Just started playing with it last night before the rain came.Rod is in the middle hole, it was in the top. still no difference.

I can run the mixture screws in all the way and theres barely any change in idle. i checked for vaccum leaks and didnt find any.

Eddies use vac for idle circut. If vac is low you need to change the springs on mettering rods. Also go to the 43 squirter nozzle.

I have an eddy 600 (1406 I believe (elec choke) and I chased a hesitation. It's a main metering lean problem. Idle the car for a minute to fill the bowls then pull the top and (car level) the fuel level should be at the slot in the float baffles (on each side). I had to richen my jets to eliminate a hesitation and the AP had an immediate and lengthy squirt so I knew that wasn't it. Runs excellent now. Do set the timing 1st ~12-20 depending on what the cam/eng wants (vac gauge method works well) then shorten the slots for 35 total (initial and total set w vac adv disconnected if a VA is used)

Does your Eddy have vaccumn or mechanical secondaries. I'm betting you have the mechincal and you need the vaccumn. I had the Eddy on my 383 (mechanical). I tried for a few years everything. Changed everything. Finally bought a Holley with the vac secondaries, bolted it on and presto the prob completly disappered. Now I need a lot better tire. Car is an automatic and smokes the tires.

Bump up the timing to around 18-20 intial first and then tune the carb from there. This will help or cure the flat spot plus idle quality as you may not be on the idle circuit if you've got the idle speed screwed in alot. This may be why the idle mix screws don't respond.

Middle or top hole for the accel pump depending on what your motor wants for intial squirt. My 360 with a 750 Eddy likes the middle hole.

You may need lighter springs if your vacuum is low and you hear a fluttering/buzzing sound plus the carb will load up & die if idling for any length of time.

Pretty soon Swingin 72 will respond with "get rid of the Eddy and buy a Holley!"

Like said above crank that initial timing up and that will let you turn the idle speed of the carb down. If you can turn the idle mixture screws in and it does not have an effect you probably have over exposed transfer slots. When transfer slots are over exposed you will never get rid of the off idle stumble.

Ok well i tried checking the timing and my good dial back matco light will not work on this car for some reason. I thought it was the msd wire,so i put a stock plug wire on still no good. I advanced the timing by highest engine rpm then checked my vaccum,only about 5. turned the a/f screws all the way IN and my vaccum is no around 12 and the dead spot is gone and engine runs 100% better. My question now, any idea why my timing lights not working ? The car has a msd coil with mallory elec distributor.

How do i get more engine vaccum without running the a/f screws all the way in. Shouldnt they be about 1 1/2 to 2 turns out?

THANKS for the help!

I'd borrow a light & (1) see what your initial is (2) see how far open the blades are open in the throttle bore (Start by turning the timing SPEED screw CCW till it's free and count the turns so you can return it to that spot). Do you have an MSD box which can play havoc w a dialback? What is the idle speed now? Is all good ex for the # of mixture needles turns does not appear anywhere near correct? For sure see where the timing is at & shorten the slots accordingly (if need be). Holler back w any new developments

The light worked on the last two cars i used it on recently. It flashes but really really slow.No msd box....... the idle now is about 900 in park.

you say turn the timing speed screw... where is that located? does that allow me to adjust the transfer slots? Thanks!!!!!!!!

turn your idle down to 700 and try adjusting the mixture screws again. At 900 the throttle plates may be open to far. Try that and see if they adjust better. If idle climbs cut it back till you have the right mixture setting then final idle adjustment.