Anyone local available to help me

[dougs bs23]

Tinkering with my quickfuel hr680 carb and cant seem to get it right,  Is anyone around the area available to drop by and lend a hand tuning this thing in. Seems to rich but id feel more comfortable having someone with more experience helping me out here.   Its on my 340 dougs headers, edel airgap intake, lunati cam model # 60403 226in@.050234ex    quickfuel primary main jet 70 secondary jet 74 idle air bleed 70/70 high speed bleed 28/28 pri nozzle 31 needle and seat 100 power valve 6.5
hope this info helps
annapolis MD close to 50& I97

[MEK-Dangerfield]

Doug,

  Is your car road worthy? You can take it for a spin and check the spark plugs after and see what they look like.

[dougs bs23]

I've been meaning to get to  :burnout:the mva for tags. Other than that it is minus bumpers which I just ordered from Dave at Roseville. But I have been playing with it on my street and even accomplished a good. 

[MEK-Dangerfield]

Doug,

  Have you looked at a spark plug or two? I'm just wondering what makes you think it's running rich? You can't go by smell, although surprisingly my car isn't bad in the odor department. I have a jet kit that has every size from 64 to 99. The only space empty is 77, so as long as you don't need those...

  Have you set the float levels? Adjusted the idle mixture screws? Do you notice any other problems?

[dougs bs23]

Float levels at half glass or maybe a bit higher, working the mixture screws keeping an eye on vacuum and rpm   will seem to be good, put in gear wants to stall out or if i put in gear and work the throttle will either stall out or backfire.  Also on initial startup runs really rough and smokes a little till it settles down after about 30 seconds or so.  I guess ill keep trying to tweek it a little at a time.  This is a new out of the box carb, when i first put it on  mix screws were only out about 3/4 turn and was popping through the exhaust  very lean so im trying to get it right,  maybe now at about 1-5/8 turn or so ots to rich        trial and error thing i guess  or maybe to much timing   about 38*at 2500

[Chryco Psycho]

if the cam causes the engine to lope at idle it will drop cylinders & send raw fuel out the exhaust .
 does it have a choke on it , if so that can be adjusted so it is not too rich while warming up , it could alos be too lean if it is backfiring as you open the throttle . Jets have nothing to do with idle but if you have less than 7" of vacuum in gear at idle in gear the power valve will open adding more fuel as well .
  I would drop by but & i am few miles away from you !!

[dougs bs23]

So i finally have a chance to look into this a little more,  after being chastized over at rhymes with farts.  I think i may need to look at timing .  Using the post here in archives about setting timing at 36/38* by measuring the balance at 2-3/8"  to find the approximate 18* mark would i simply measure the balancer at 1-3/16" ?    pulled plugs and black from being to rich so if i get the timing backed off some i'm thinking it will help me set the carb more closely and get the idle speed to around 800 or so.    And ill also put the gauge on and see what vac im drawing, and list results here

[Chryco Psycho]

yes you can put a second line @ 1 3/32 for 18 *
First get the float level set . Make sure it is not flooding out the vent tubes from excessive pressure .
 Next you need to know what vacuum you make at idle , ,  in gear if Auto,  if it is low 4-8" the powervalve is a problem then by a power valve rated at least 1" lower than that . SO if you make 4" of vacuum at idle in gear you need a 2.5 powervalve so it will say closed .
If the plugs are black  it is rich not just smell , how are the idle mixtures set ? gently bottom all the screws & back them out 1.5 turns then turn them in or out equally to adjust . It it makes no difference whee the idles screws are set then the throttle is open too wide to keep it idling , you may need to drill holes in the throttle plates so the throttle can be closed to regain idle sensitivity . If the idle seems ok then you may just be to rich in the jet circuit so bigger bleeds or smaller jets are needed .

[dougs bs23]

Thanks Neil  im going back to tinker with it and ill post what i find.  so at 18* at idle with the vac advance disconnected and blocked off? and my float levels are slightly above half glass

[Chryco Psycho]

16-18* yes around 800 - 1000 rpm
 drop the floats to 1/2 should be about 1/4 turn down

[dougs bs23]

so now im at approx 18* idle speed around 920 with 13" vacuum, seems alot better and doesnt stall out when i drop it in gear. but,,,,, seen a big difference  after i blocked off the booster vac line which tells me maybe a leaking booster or bad check valve,  also when i snap the throttle i get a little pop back through the carb,  4 corners are all set at 1-1/4 turn out,, im getting closer 

[Chryco Psycho]

. I am glad is is better ,so you might need a larger squirter to get more fuel in as the throttle is opened to sstop the pop . I have often seen leaks into the booster .

[dougs bs23]

One more question,  Right now I have the dist vac connected to the "full manifold vacuum port on the carb, is this right or should it be on one of the "timed spark ports" on the carb?  It's a factory dist, original to the engine i believe.  Or does it not make a difference?    As for changing the bleeds, the idle bleeds are 70 and high speeds are 28

[Chryco Psycho]

with it connected to manifold you have full vacuum at idle & it backs off with RPM at the same time the Mechanical is doing the opposite pointless , I disconnect the vacuum advance & plug the port on the carb

[dougs bs23]

So now my next question is,  how would fuel pressure affect this?  Have a mechanical pump and 5/16 lines no return but do have the vapor return setup but line is capped in the engine compartment.  Pressure fluxuates (i guess with the cam action of the pump) between 4 and 9.  Would a regulator be a good idea and how would this (if any) affect the pump?