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Strap on the JATO
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305 Posts
Discussion Starter #1
Hi guys, I need a little advise as to which way to go about
this; I have a 454 9.5/1comp, holley 800dp marine 9022 carb,
Edelbrock Victor Jr (rect), Crane ZHR-288 cam(226/234 @.050),
a little over 15in of Vacuum at Idle(900rpm). I'm having trouble
getting the idle mixture correct. The primary's are 1 1/2 open from
seated & the secondary's are 1/2 from seated. If I turn one side of
the idle mixture screw all the way in, nothing happens. If I leave it
and go to the other side I can finally get the motor to start to die
w/ 1/2-1 turn in (set at 1 1/2 out). I'm trying to keep from drilling holes
in the primary plates. Should I maybe open the secondary plate a little
and close the primary respectfully to lessen the exposure of the transfer
slot? I'm just learning these holley's from having Edelbrocks.......
Thanks for any input in advance!!
 

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Boat Nut
Joined
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5,131 Posts
Hi guys, I need a little advise as to which way to go about
this; I have a 454 9.5/1comp, holley 800dp marine 9022 carb,
Edelbrock Victor Jr (rect), Crane ZHR-288 cam(226/234 @.050),
a little over 15in of Vacuum at Idle(900rpm). I'm having trouble
getting the idle mixture correct. The primary's are 1 1/2 open from
seated & the secondary's are 1/2 from seated. If I turn one side of
the idle mixture screw all the way in, nothing happens. If I leave it
and go to the other side I can finally get the motor to start to die
w/ 1/2-1 turn in (set at 1 1/2 out). I'm trying to keep from drilling holes
in the primary plates. Should I maybe open the secondary plate a little
and close the primary respectfully to lessen the exposure of the transfer
slot? I'm just learning these holley's from having Edelbrocks.......
Thanks for any input in advance!!

There is a screw for the secondary plate stop, accessed from the bottom of the carb, thru the base plate. I like to remove that screw, and run in an Allen set screw from the top side of the base plate, this allows adjustment while still bolted on the engine. All the four corners should be set the same, if you have one that is not functioning, you have some blockage some where in the circuit. hope this helps
 

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Strap on the JATO
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305 Posts
Discussion Starter #3
the holley rebuild instructions say to open the primaries to 1 1/2
from seated and the secondaries to 1/2 from seated? Is it easier to
tune with them the same open adjusted(1 turn open both primary & secondary)?
 

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2,234 Posts
At what RPM are you trying to get it to idle? With that combo, I would think it would want to be at around 1100 R's, which may require a small hole in each primary butterfly, you can open up the secondary butterflies to compensate but may result in an off idle hesitation, a numerically larger power valve may help this out, the easiest way to see if you have a carb problem in this case is to give the engine a little manifold vacuum leak and try and make your adjustments, if you have a circuit that won't adjust, it may be time to take a closer look at that metering block for some debris.

The vacuum leak needs to be closed off when done and the adjustments changed again, but it will make "slop" count the same as "skill".

Once adjusted all four corners may be slightly different as far as "turns out" but should end up quite close..

Good luck.

GT :)hand
 

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Strap on the JATO
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305 Posts
Discussion Starter #5
With this much vacuum I shouldn't be having this problem.
The metering plates are clean, all the ports are good.
 

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This is the same problem I had with an 850! Did get some good advice but this is what I learned! Check timing where are you set, all four corners should be close to the same! Timing if to high will cause preingition and give you hell and will cause the mixture screws to be mix settings! Set all four corners 3/4 of a turn out and play with the plates at lowest possible RPM! You might have to pull the carb off to check the transfer slots to make sure you haven't opened them up too much! When all is set to smoothest recheck the mixture screws again! Good luck! WT:)devil
 

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Cantard
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5,017 Posts
This is the same problem I had with an 850! Did get some good advice but this is what I learned! Check timing where are you set, all four corners should be close to the same! Timing if to high will cause preingition and give you hell and will cause the mixture screws to be mix settings! Set all four corners 3/4 of a turn out and play with the plates at lowest possible RPM! You might have to pull the carb off to check the transfer slots to make sure you haven't opened them up too much! When all is set to smoothest recheck the mixture screws again! Good luck! WT:)devil
Awesome advice!! x2
 

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Strap on the JATO
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305 Posts
Discussion Starter #8
This is the same problem I had with an 850! Did get some good advice but this is what I learned! Check timing where are you set, all four corners should be close to the same! Timing if to high will cause preingition and give you hell and will cause the mixture screws to be mix settings! Set all four corners 3/4 of a turn out and play with the plates at lowest possible RPM! You might have to pull the carb off to check the transfer slots to make sure you haven't opened them up too much! When all is set to smoothest recheck the mixture screws again! Good luck! WT:)devil
Widetrack, This is EXACTLY what I was looking for! Thanks alot!! I only have mixture screws on the primaries. The initial timing is at 18deg w/ a total of 34. Maybe too much initial?
 

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Cantard
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5,017 Posts
Widetrack, This is EXACTLY what I was looking for! Thanks alot!! I only have mixture screws on the primaries. The initial timing is at 18deg w/ a total of 34. Maybe too much initial?
Not enough. I would try bumping it up to atleast 28.
 

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Cantard
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5,017 Posts
28???? O.K, i'm confussed.....Wouldn't that make it harder to start & cause pre-ignition?
Will still start fine at 28. 99% of the stuff I do is all locked down with no problems starting. I bet if you locked yours in at 34 you would have no problems. What do you have for ignition? Going to be hard to only advance 6 deg.
 

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Boat Nut
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5,131 Posts
Will still start fine at 28. 99% of the stuff I do is all locked down with no problems starting. I bet if you locked yours in at 34 you would have no problems. What do you have for ignition? Going to be hard to only advance 6 deg.
Your kidding right, I cleaned the teeth off my ring gear in two spots, and sheared the bendix off the starter. This was a mishap, the advance return springs rusted away, and broke. Distributor was stuck in full advance....KAPOW!! I agree, run as much as you can for initial advance, and let the mechanical bring in the rest. I had a good battery, and a good starter, but the motor got the best of it.
 

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2,426 Posts
Your kidding right, I cleaned the teeth off my ring gear in two spots, and sheared the bendix off the starter. This was a mishap, the advance return springs rusted away, and broke. Distributor was stuck in full advance....KAPOW!! I agree, run as much as you can for initial advance, and let the mechanical bring in the rest. I had a good battery, and a good starter, but the motor got the best of it.
12 degree's Idle 29 total, starts great in gear idles all day. MSD dist. that is adjustable.............. works for me.
 

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2,426 Posts
12 degree's Idle 29 total, starts great in gear idles all day. MSD dist. that is adjustable.............. works for me.
Also, I've had problems with restricted metering blocks, took them off blew them out and got them to adjust, make sure your base gaskets are not leaking air also, and if the carbs are old sometimes they suck air through the throttle shaft..................never over look the basic easy stuff !
 

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Strap on the JATO
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305 Posts
Discussion Starter #15
Will still start fine at 28. 99% of the stuff I do is all locked down with no problems starting. I bet if you locked yours in at 34 you would have no problems. What do you have for ignition? Going to be hard to only advance 6 deg.
Petronix HEI, I'll try spraying some carb cleaner at the shafts & see what happens. I just rebuilt the carb to holley specs & checked every fuel passage w/ air & carb cleaner.
 

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Cantard
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5,017 Posts
Your kidding right, I cleaned the teeth off my ring gear in two spots, and sheared the bendix off the starter. This was a mishap, the advance return springs rusted away, and broke. Distributor was stuck in full advance....KAPOW!! I agree, run as much as you can for initial advance, and let the mechanical bring in the rest. I had a good battery, and a good starter, but the motor got the best of it.
What was your total with the springs gone? Problem isnt really the spings missing so much as the weights kicking the advance. To light a spring also does this .... worse that locked. I just set up a 496 100% street car had these problems. Locked it out at 34 and starts like a dream. If its real hot 1/16 on the throttle can do wonders.
 

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Cantard
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5,017 Posts
Petronix HEI, I'll try spraying some carb cleaner at the shafts & see what happens. I just rebuilt the carb to holley specs & checked every fuel passage w/ air & carb cleaner.
If you have the carb off again make sure the rear throttle plates are open/closed enought to make the slot that is cut into the throttle plate makes a square not enought or to much can make it search.
 

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Strap on the JATO
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305 Posts
Discussion Starter #18
The rear plates are at 3/4 turn open from seated, Holley says to
start at 1/2 turn for secondaries & 1 1/2 for primaries. I tried
messing w/ it a little, but my pumps apart right now messing w/
wear ring crap.......
 

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Cantard
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5,017 Posts
The rear plates are at 3/4 turn open from seated, Holley says to
start at 1/2 turn for secondaries & 1 1/2 for primaries. I tried
messing w/ it a little, but my pumps apart right now messing w/
wear ring crap.......
Probably not enough.... kinda thing you have to give a visual.
 

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I'm No Expert
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3,139 Posts
Dont know anything about those carbs but i'll tell you about a problem i had. After i fixed a vacum leak my idle was high, i couldnt get it down below 1100 RPM. I kept thinking i had a worse vacum leak because with the initial one it would idle as low as 800 rpm. Anyway, i had the same problem where turning in the idle screws on all 4 corners wouldnt kill the motor. I am running dual carbs and i was told that the idle circuit needs to probably be shrunk. On the 660's they put wire in them to shrink it. Anyway when checking my carbs they had already been shrunk but one thing that we found was that the secondary plates where not closing enough and what was happening was that the idle circuit was being bypassed. This is why the motor would not die when setting all the idle screw's in. We took alittle out of the sec plates adjuster (on my carbs it's a screw on the carb base/plate on the right side) and once we did that we were able to kill the motor by setting the idle screw's all the way in, also my idle dropped down to where it could stall the motor. I would check this first, especially if you adjusted this screw when putting it back in. On my carbs if you pull the carbs, flip them over and open the sec's you can see a small rectangular slit, the sec plates when closed should cover this/block it off. On mine it looked like it was but just needed to be closed a hair more.
 
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