Thread: Still having complications

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i have found that this thing has more mood swings than a woman. ive got a 427 wtih flat tops 291 heads not sure on cam size air gap intake 850 mighty demon msd street fire distributor i believe a holley red pump,cell with half inch aluminum line front to back with regualtor, pressures carries 7-7.5. when it runs it runs great. At times i can drive it with no problems other times it seems to be flooding or running out of fuel. while cruising doesnt matter at what speed,if you try to gain speed with a little pedal push it wants to spudder like its running out of fuel but if you crack it wide open it will try to pick up and run and it doesnt do it all the time.. Can anyone help before i accidentley leave these monster on the rail road tracks???

Sounds like you need to rebuild that carb accelerator pump and maybe jets??? I would at least start there and see what happens then... Others will be along with other sugestions I'm sure

if you push the clutch in when it acts up it will take throttle no problem and it doesnt act like its running to rich? Could the carb be to big?

427 with flat tops ?boy that thing has no compression .cam could be to big for stall and low cr will make engine harder to tune in .but sounds like carb and timming thing. look at your accelerator pumps on the carb. look at were you are picking up the fuel in the tank low point sump is the best if not could be sucking air. heat could be vapor locking .could be lack of a fuel filter or floats not set right. well i see you have a stick so no stall

Pat was typing a bit ahead of me - I wouldn't think an 850 is not too much carb for the 427. Like Charlie, my first thought was accelerator pump - sounds like you're not getting enough transition fuel to carry you through the increased air flow, before the jets can react. Have you pulled the plugs to see how they look for main jet selection?

Do you have a demon with an idle-eze base plate?

You have too much fuel pressure--lower it to 3 lbs for sorting this out, check float levels--demons have site plugs

change power valve to 3.5 or possibly 4.5

what size squirters do you have and are the pump cams pink?

pat im guessing with the 921 heads ive got 9.5 9.8-1 compression yes a little low if i was having accelerator troubles would i be able to push the clutch in and rev with no problems? the cells outlet is on the bottom front but it does it with a full tank also, ive thought about vapor locking but not really sure how to check for it the floats are set a little higher than the middle of the glasses and new fuel filter.roger ive pulled the plugs after a highway run and they arent paper sack but they arent gas fouled seems a little rich but i didnt think it was enough to cause any issues.jerry, yes it has idle ease. 3lbs? the book shows 6-7 psi but i will try it to see what happens, it came factory with the power valve eliminator the squirters are 31s and the cams are pink

I don't believe that it came with pv eliminator--I said to lower it to 3 to eliminate too high pressure being the cause--i like 4 - 4 1/2 when i'm done--

for now---put a 4.5 pv, 78 pri 80 sec jets

have you had carb apart? some 3 or 4 years ago would have enough chips from machining in them to fill a teaspoon

turn the base plate over and set throttle plates so the transfer slots show about a .020 square hole(the transfer slots often have a big chip/burr which you can see from the top side)

set idle with the idleze screw tp around 850
if you need to lock out the timing you can use safety wire around the pins for the advance springs--i do this til i find out where the engine wants it to be---

what jets do you have in it now?

jerry you are correct sorry i was reading wrong it does have a primary power valve its shows to have 6.5 out of the box but ive never had it apart. the throttle plates have been set with the .020 square. if the power valve was blown would i have idleing issues? and locking out the timing do you mean wireing the weights to where they are fully open?

either way on the dist---just so it cant move--find out where engine is most responsive and then set max to there--change pv to 3.5 if you can find one otherwise 4.5

and what jets do you have now???

on the jets im going to assume it still has the factory 85 pri 93 sec ive never had the carb apart and the guy i bought it from said he didnt either.i have been told this carb has pv blow out protection,is this correct? what exactly does the pv do? sorry for the dumb questions im just a young pynk kid trying to learn

Power valve richens mixture by 5 to 8 jet sizes when vacume is lower than valve rating---

for now move 85s to seconary and get put some 78-81 or so in pri with a lower rating pv

set timing to high 20s(28,29) to max of 36-38

on the starter--do you have GM starter bolts holding it to block, and the brace from starter to block on front of it??

and do the accerator pumps give a good squirt of fuel when you work the throttle???

the starter is a mini, bolts arent factory but they are knurled no there isnt a bracket, is the bracket like the one for a small block bolts to the starter then to the side of the block? as random as this thing acts up do you think i might have some trash in the front bowl or some where maybe on occasion it floats up and blocks an orfice?

I don't think anything YET---but if you take the carb apart look into the areas behind the main jets-(looks like a bat cave!!!!) always some hanging trash from threading process---

but, you got to get to basics---fresh, clean fuel, pressure right, floats rite ht, power valve proper setting, etc

i drop the pressure tonight and see what that does and if no go there i pull the carb apart and make sure shes clean. thanx for the help ill repost when i make some progress