new motor 10.2:1 c/r 280h cam topline heads 200/64cc 1.5 rocker perf.rpm 1 5/8" shortys into 2 1/2" pipe into 3" 40 series and nothing on the back side of the mufflers.this damn 1407 carb is upsetting me extremely rich at idle,mixture screws bottomed out and the rpm's go up no stumble or stall?????what causes this??is this carb to big???edelbrock support says that this carb should perform for me with the stock jets and rods to change to heavier spring due to cam issues.all the damn money i've spent i cant afford a new hp until july,but would like to enjoy the fruits of my friggin pocket and labor without tears coming to my eyes from unspent gasoline.
thanx
shane

Shane, did you get the calibration kit for the carb yet? They are very easy to work on and adjust, even for an amateur mechanic like me. I had the exact same 1407 carb on a BB 396 and it ran rich in stock form, I ended up jetting it down two sizes, but after that, it ran like a top for several years. I've got a Holley 3310 on my current 454, and the calibration kit is just sitting useless on a shelf in the garage, if you're interested in it, shoot me an email and I'll make you a good deal on it, I think they're like 50 bucks new in Jeg/Summit.

First you need to pull the carb off and check to see how much of the transfer slot is exposed. Also, how's your ignition? Do you have it timed right? What does your curve look like? Ignition always comes first.

ignition comes first at idle????msd 6al accell hei coil msd 8.8's...transfer slot?????
just rebuilt it last night(had it off).didnt know edelbrock had a transfer slot.were is it???
shane

dont think its a timing issue this thing is running rich.....
why no stumble or stall with mix screws bottomed out.
shane

okay been surfin' see transfer slots will this cause a rich condition at idle if exposed??do i need to drill the holes in primary blades..
shane

Lose the Edelbrock and get a Holley if its performance that you are seeking graemlins/thumbsup.gif

i know i know night and day but cant afford one till early july,i wanna 750 hp,
but anyway the transfer slots are exposed almost 1/4" is this it?is this my prob???
do i drill holes in the primary blades 1/16" or what?edelbrock carbs are definitely not performance oriented.how do they sell "total power packages"without problems like this??weak cams?
shane

whats your timing set at? without the vacuum advance hooked up? I'd have it set at 10-12* btdc at least,sounds like its retarded to much.

as suggested above, check the timing. if the timing is retarded it will cause the idle to be slow and weak, which is then compensated for by turning the idle speed screw in till the engine will stay running by itself. then the throttle is too far open causing the exact condition you have.

with that cam you'll need at least 12-14 degrees initial timing with no vacuum hoses hooked up to the distributor, it might even need more than that. get that straightened out and you'll be amazed at how much better your carb works.

You'll probably have to back the idle speed screw out 3 or 4 turns and the idle mixture screws out around two turns.

Tom

ok i'm getting upset.borrowed a light set at 13
no advance hooked,went and bought 107 jets.still billows smoke at idle and under driving cond.it is spitting and popping and starving for fuel,at least with the 113's it ran good just rich now it runs like crap and is still rich at idle,hooked up the light and was pretty close by ear @ 10 degrees but put to 13 at your advice,mixture screws turned all the way in and still no stumble?????????????????????????????????
i still love my bowtie
shane