Reply With Quoteis running fat, fumes arent to bad tho.. vaccum is at 14..
I had a friend who bought one and was having the same problems you are. What we found was that the motor needed 35 squirters, and an 8.5 PV.
What is your manifold vaccum at idle and at cruising 45-50 mph?
What we also found is that if we opened up the idle screws so that it was WAY rich the stomp and stall would start to disappear this is where we started going up on the squirters. Granted we only went from the 33's supplied to 35's. The power valve was selected because at idle (adjusting the idle screws to achieve maximum vaccum) I could get between 10-11. I tried a 9.5 and it was too much, as soon as i put the 8.5 with the 35 squirters, readjusted the idle mixture screws ALL hesitations stopped.
The circuits go as follows:
Idle screws - well they meter the amount of fuel at idle.
Squirters - When you stomp the loud pedal from idle or at cruise they make up for the sudden large amount of air.
Power Valve - When you open the throttle quick vaccum drops this opens the valve and richens the midrange circuit under acceleration until vaccum again rises.
Jets - Although they do work somewhat throughout the RPM range, they are mainly for the top end metering of fuel only.
In my opinion jets aren't going to do crap until you get the right squirter and power valve for your combination.
Try richening the idle screws 4 corner could be 2-2.5 out (basically to the point that you cannot stand to be in the garage because of the fumes) if the stumble begins to go away they you need to up your squirters.
One other thing have you messed with the secondary idle screw?
is running fat, fumes arent to bad tho.. vaccum is at 14..
is running fat, fumes arent to bad tho.. vaccum is at 14..
is it running fat due to upping the jets? or because you've backed out the idle screws? What jets do you have in it now?
If your running 14 vaccum at idle you're going to need in the neighborhood of a 11.5 PV to richen the circuit. I'm guessing you have the standard 6.5.
What squirters do you have?
My guess/recommendation would be 35 squirters, 11.5 PV, 1 to 1.5 turns on the idle mixture screws and 70primary-74secondary(to start) jets.
for sure on all the questions. thinking the jets are 73 77 or close to that, going to tune at the dyno for last effort, buddy is going to go in halves for the day, then i suppose there will be no guess work! but im going there with a new holley 650 also,, hopefully we will come across something that youve been explaining, but if not carb is coming off!!!!! motor put some gd hp. to the rear wheels last time we were there!!
for sure on all the questions. thinking the jets are 73 77 or close to that, going to tune at the dyno for last effort, buddy is going to go in halves for the day, then i suppose there will be no guess work! but im going there with a new holley 650 also,, hopefully we will come across something that youve been explaining, but if not carb is coming off!!!!! motor put some gd hp. to the rear wheels last time we were there!!
That's cool. I'm sure you'll get it figured out, these items i've discussed are what i've learned from John Avery who builds my carbs for my Super Stock and when i helped my buddy with his demon i called their hotline and they told me it's the same thing. The people i know who are really into the demons say that they are a little more exacting to get right but when you do get'em there they will run better in a multitude of eviroments. The holley's seem to be more prone to weather and altitude changes than the demons.
Good luck hope it works out for you. I'll be checking back to see what you found out and tried.
James
PS if you want you can give me a call, 702-266-7322 i'll be at the drags all weekend so i won't be checking back here until monday.
thanks alot james! greatly appreciated! ive heard the same thing, thats why i bought that carb! it is just timid to say the least..
It sounds like you need a bigger pump shot to cover up the time for the mains to take over. I would go up 2-3 sizes on the pump nozzels.
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