Holley Carb Help !!!!

[Jeanyus]

OK I'm lame when it comes to tuneing carbs. I just switched from 2 Holley 600 vacuum secondairie carbs to 2 holley 750 (6109) tunnel ram carbs.
The 600s worked good , but I am having trouble with the 750s. I can't get it to idle, it starts out at 1200 rpms and slowly looses rpms down to 500, then dies. When I stomp the pedal, the engine runs up to 6000, then starts missing and flutters at 5600 rpms. The plugs show that I am a little rich.
Try not to laugh at my fuel lines, I didn't want to spend $350.00 on fuel lines If I can't get these carbs to work.
http://www.hotboatpics.com/pics/data/500/5859fuellines.jpg
http://www.hotboatpics.com/pics/data/500/58592fuellines.jpg
http://www.hotboatpics.com/pics/data/500/5859fuelpump1.jpg
I have 7.5 lbs fuel pressure,and it looks like it drops to 7 at full throttle.
I was thinking about bypassing the fuel pressure regulator, to see if that helps.
I also have a billett fuel tank selecter valve, where I can choose right left or both, when I tested the boat I was only on 1 tank.
With my current fuel system I can get it to run good with these:
http://www.hotboatpics.com/pics/data/500/5859600_s.jpg
and I can get it to run near perfect with this:
http://www.hotboatpics.com/pics/data/500/5859torker.jpg
I'm thinking about putting the 850 on and go boating. Help!!!!

[FASTRAT]

welll....i know what i would do...put the 850 & manif. back on & go have fun...play around with the tunnel & 750's in the off season...sure it looks impressive...but...why beat ur brains out to get it to work...i would add a 1" or 2" spacer under the carb tho...to dissapate the heat...just my .02 cents worth
fastrat

[396_WAYS_TO_SPIT]

welll....i know what i would do...put the 850 & manif. back on & go have fun...play around with the tunnel & 750's in the off season...sure it looks impressive...but...why beat ur brains out to get it to work...i would add a 1" or 2" spacer under the carb tho...to dissapate the heat...just my .02 cents worth
fastrat
Agreed!!!!

[Wicked Performance Boats]

Have you checked the float levels? Do you know what jets are in it? Start the boat with the scoop off and see if the carbs are trickling fuel in the throats. You may have a needle and seat leaking or bleeding past so it's dumping fuel into one carb. Budlight

[steelcomp]

Ron, the idling issue sounds like it could be a vacuum leak. When it idles and dies, is it dying because it's loading up, or is it dying because it runs out of gas?? Another thing that comes to mind is that when using rubber hose, it's easy to get little pieces of rubber in the system and possibly clog a needle and seat. This would allow a bowl to overfill and run into the carb at idle, killing the motor after a few seconds. This is what Bud Light was talking about as fat as looking in the carb while it's running to see if fuel is trickling. I also see something in your pic that you might want to change...it's better to get the fuel filter in front of the pump rather than behind it. Pumps don't suck very well. They're made to push. You say you have 7 lbs at full throttle, though, so it may not be an issue. Is that 7 lbs steady or does it fluxuate?
Call me with any questions.

[78Eliminator]

Where are you located?

[INEEDAV]

OK I'm lame when it comes to tuneing carbs. I just switched from 2 Holley 600 vacuum secondairie carbs to 2 holley 750 (6109) tunnel ram carbs.
The 600s worked good , but I am having trouble with the 750s. I can't get it to idle, it starts out at 1200 rpms and slowly looses rpms down to 500, then dies. When I stomp the pedal, the engine runs up to 6000, then starts missing and flutters at 5600 rpms. The plugs show that I am a little rich.
Try not to laugh at my fuel lines, I didn't want to spend $350.00 on fuel lines If I can't get these carbs to work.
http://www.hotboatpics.com/pics/data/500/5859fuellines.jpg
http://www.hotboatpics.com/pics/data/500/58592fuellines.jpg
http://www.hotboatpics.com/pics/data/500/5859fuelpump1.jpg
I have 7.5 lbs fuel pressure,and it looks like it drops to 7 at full throttle.
I was thinking about bypassing the fuel pressure regulator, to see if that helps.
I also have a billett fuel tank selecter valve, where I can choose right left or both, when I tested the boat I was only on 1 tank.
With my current fuel system I can get it to run good with these:
http://www.hotboatpics.com/pics/data/500/5859600_s.jpg
and I can get it to run near perfect with this:
http://www.hotboatpics.com/pics/data/500/5859torker.jpg
I'm thinking about putting the 850 on and go boating. Help!!!!
What kind of vacuum are you holidng at idle? What power valves are in the carbs. Also, what jets are in the carbs? What kind of engine are we dealing with here? How recent were the carbs rebuilt?

[Beer-30]

Assuming you have tuned the idle mix screws, running, in the water, warmed up, I would look at the power valves. Someone may have put 6 or 7s in them and you could be pulling PV fuel at idle.
After you have it idling, start looking at WOT fuel press. Sounds like you may be at limits.

[Jeanyus]

I live in northern Ca. Near Sac. any carb guys in my area ?
The engine is a 10:1 427 solid lifter cam rectangle port closed chamber heads.
The carbs are freshly rebuilt. Not done by me. I am a foundation and concrete contractor, I don't have carb skills.
http://www.hotboatpics.com/pics/data/500/5859nice750.jpg
I set the float levels in the garage, with the front of the boat jacked up to simulate the way it sits in the water.
I tried turning the air fuel mixture screws at the lake, but did not improve the idle.
I cant check the vacuum at idle, cause I can't get it to idle.
The jets are 76 in front and 75 in back, I think the power valves are 5.5 ?
I just pulled a plug, they are a little wet with gas.
http://www.hotboatpics.com/pics/data/500/5859sparkplug.jpg
I will run it this weekend and look for fuel dripping in the carbs.
I put a lot of money,time, and effort into this dual cab setup, sure hate to give in and run the trusty 850.

[steelcomp]

These carbs are basically stock 750dp (6109) stock jetting, stock PV's, stock squirters. I sold them to Ron, and never used them myself, having bought them used. I rebuilt them using all Holley parts, and inspected them thoroughly, and didn't find anything wrong with them, at all. They had been sitting for a number of years, and were very dirty, but mechanically sound, with no internal modifications. The mods to the choke horn and tops of the throttle bodies were already done, although a little rough, so I cleaned them up, as well.
Mains...75 pri, 76 sec.
PV's...85 pri, none sec.
Squirters...025 pri, .032sec.

[Beer-30]

These carbs are basically stock 750dp (6109) stock jetting, stock PV's, stock squirters. I sold them to Ron, and never used them myself, having bought them used. I rebuilt them using all Holley parts, and inspected them thoroughly, and didn't find anything wrong with them, at all. They had been sitting for a number of years, and were very dirty, but mechanically sound, with no internal modifications. The mods to the choke horn and tops of the throttle bodies were already done, although a little rough, so I cleaned them up, as well.
Mains...75 pri, 76 sec.
PV's...85 pri, none sec.
Squirters...025 pri, .032sec.
Hey Steelcomp, with 8.5 PVs, and he has a solid cam that is probably pretty radical, I am thinking he's into the PVs at start-up. Drop those to about 4.5s. Especially since he says the idle mix screws aren't doing anything. The carbs are giving fuel other than the idle circuit. Floats maybe too high, allowing dribble out of the venturies?

[steelcomp]

I completely agree, especially with smaller motor. Don't think floats are as much an issue as PV's. I don't know what Ron's cam is, and I'm trying to reach him.
Zev...CALL ME!!

[Beer-30]

I completely agree, especially with smaller motor. Don't think floats are as much an issue as PV's. I don't know what Ron's cam is, and I'm trying to reach him.
Zev...CALL ME!!
As rich as he is, and like you said, smaller cubes, it may be happy with PV block-offs. You are supposed to go up like 3 jet sizes if doing so, but I ran an 850 on a 340 Chev w/o PV and it was awsome. Probably wouldn't need to re-jet. Plus, no more PV issues. Might be easier than guessing which PV to use?

[Fiat48]

On the float levels....don't use the sight glass. Too many angles and variables. Remove the bowls..turn the bowl upside down. Looking into the float bowl you should see the float hanger screws and the top of the float should be flush with the "tops" of those screws.
Hope I explained that good enough.
And for what it is worth. Ran a lot of 6109's. Jetted them 78's and 80's. 6.5 power valve. Small restrictor wire in the in the idle circuits (Ineedav can tell you how). Big cams sometime require little holes drilled in butterflys. Excellent carbureator and about all anyone needs as far as cfm unblown.
Just remembered...6109's are side hung floats. Duhhh. Just level the float in the bowl. You'll see it.

[steelcomp]

On the float levels....don't use the sight glass. Too many angles and variables. Remove the bowls..turn the bowl upside down. Looking into the float bowl you should see the float hanger screws and the top of the float should be flush with the "tops" of those screws.
Hope I explained that good enough.
And for what it is worth. Ran a lot of 6109's. Jetted them 78's and 80's. 6.5 power valve. Small restrictor wire in the in the idle circuits (Ineedav can tell you how). Big cams sometime require little holes drilled in butterflys. Excellent carbureator and about all anyone needs as far as cfm unblown.
Just got off the phone with Ron. Several things to check, but it seems we'll get it straightened out. Not running a big cam, float levels seem OK. May have to go to smaller PV's or eliminate them...I prefer keeping them. Might need a couple fuel system mods, but nothing major. I think from the rubber lines, he's got crap in the system, ahead of the filter.

[Beer-30]

Yeah, you'll get it worked out. Happy hunting.

[Jeanyus]

I just checked float levels. Front carb, front bowl, gas drips out at a fast drip.
Rear carb, back bowl seems low. Other 2 are OK.
Here are the cam specs.
Part Number/Work Order Number 01355
Engine Application 396-454 CHEVY
Grind Number 292FDP
ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Duration: 292º Lift: 0.595 Clearence Hot: 0.022
EXHAUST: Duration: 300º Lift: 0.621 Clearence Hot: 0.024
The specifications listed above are based on a rockerarm ratio of 1.7 IN
1.7 EX
RECOMMENDED VALVE SPRING INFORMATION:
Part # 68340 Single Dual X Triple
Approximate spring pressure: valve closed: 120/130 LBS.
valve open: 360/380 LBS.
24.0
BTDC 19.0
ATDC
ABDC
50.0 61.0
BBDC
The information below is for degreeing cam only. Correct only at .050" tappet lift.
INTAKE Opens: 24.0 BTDC
Closes: 50.0 ABDC
EXHAUST Opens: 61.0 BBDC
Closes: 19.0 ATDC
LOBE SEPERATION 107º
Duration at .050" Intake: 254
Exhaust: 260
LOBE LIFT Intake: 0.35
Exhaust: 0.365

[Beer-30]

Looks like a nice cam.
Was there any good Holley adjustment specs in that issue of Better Homes and Gardens? :D

[INEEDAV]

If you would like all my notes on setting up a 6109 750 let me know, I have a lot of information that I would share. Fiat48 walked me through rebuilding and setting mine up, they work great now.

[steelcomp]

Ron, I see your cam has a little more wind than I expected. Those are some fairly healthy .050 numbers. Vacuum could definately be an issue. These carbs for me, out of the box, have always been mostly (I say mostly :wink: ) a bolt and go deal. Running a pair on a friend's 467 in his v-drive (12:1, 270/276, .637/.631 108*) and they are dead stock, and are aaaaawsome! Ron's deal will take a little tuning, but with all this help, he can't go wrong. I wish I lived closer, Ron. Sorry I can't be there to help. :frown:

[Jeanyus]

If you would like all my notes on setting up a 6109 750 let me know, I have a lot of information that I would share. Fiat48 walked me through rebuilding and setting mine up, they work great now.
It would be great to see your notes. I will PM you my E-mail address.
Wasn't any info in that magazine, but I got some Ideas and built a really nice trellis for my wife. I get boat parts, she gets a trellis, it was a good trade for me.
http://www.hotboatpics.com/pics/data/500/5859trellis.jpg
I also built this retaining wall, and did the concrete, now I have a place to run my boat.
http://www.hotboatpics.com/pics/data/500/5859concrete.jpg
I could only run the boat for a few seconds in the garage bofore the fumes drove me out.
Doing all this stuff in my spare time would explain why my boat is not running good yet.

[Moneypitt]

Check the tiny little bleed holes above the inner contures/venturi areas of the carb. The are 4, 2 front, 2 rear. If they are clogged up, the carb will not idle. I use a strand of multi strand wire to make sure they are open.......Just a thought if the carbs were sitting and dirty, these bleed holes are so tiny it doesn't take much to clog them up.............MP

[Wicked Performance Boats]

Steelcomp said he just freshened them up! Pull the bowl that was trickling and pull the needle and seat and clean them. Install needle and seat, turn adjusting screw till top of float is parallel with housing w/ housing upside down. Then turn in srew 1/2 turn, lock down and reinstall. If you found any dirt or black rubber in bowl, do the same with other bowls. Budlight ps. Is that POT your wife's growing in that pic? j/k

[Jeanyus]

I took off the bowl on the front carb, no junk in the needle seat.
I don't see any flaot hanger screws to line the float up with.
http://www.hotboatpics.com/pics/data/500/5859float.jpg
Should I put smaller power valves in, while I'm here, or just run it and look for dripping gas in the carbs.
http://www.hotboatpics.com/pics/data/500/5859powervalve.jpg
These carbs are really clean, I think we can rule out dirt, rubber or junk in them.
http://www.hotboatpics.com/pics/data/500/5859holleyinside.jpg
I am fairly confident that the float levels were close enough to make it run.
Whats the next step?

[INEEDAV]

I took off the bowl on the front carb, no junk in the needle seat.
I don't see any flaot hanger screws to line the float up with.
http://www.hotboatpics.com/pics/data/500/5859float.jpg
Whats the next step?
Float level looks possibly a tad low, are the others the same? Set the float where the top of the float, the flat part, is parallel to the bowl.
How far in/out are the idle screws?
WIth your cam, and the fact that the idle screws are not doing anything I think you need to look at drilling the holes so you can set the throttle blades where they need to be and possibly later putting a restrictor in the idle bleeds.

[Jeanyus]

The back bowl off the rear carb.
http://www.hotboatpics.com/pics/data/500/5859backbowl.jpg
Looks like my float levels are too low. When I drained the fuel out of this one 2 small pieces of rubber were in the fuel. I took the needle and seat out, nothing there. I checked the jets also they are clean.
Tomorrow I will pull 1 carb, get the other 2 bowls off. Set the float levels, by making the top of the float paralell to the bowl tops. Put everything back together and run it.

[INEEDAV]

The back bowl off the rear carb.
http://www.hotboatpics.com/pics/data/500/5859backbowl.jpg
Looks like my float levels are too low. When I drained the fuel out of this one 2 small pieces of rubber were in the fuel. I took the needle and seat out, nothing there. I checked the jets also they are clean.
Tomorrow I will pull 1 carb, get the other 2 bowls off. Set the float levels, by making the top of the float paralell to the bowl tops. Put everything back together and run it.
Since you did find some rubber it might be worthwhile to blow air through the carbs passages to make sure they are not clogged with anything.

[Jeanyus]

Here is my progress so far. I took both carbs off, and took all the bowls off. 2 of my float levels were low, corected that problem. 2 of the bowls had small pieces of rubber in them, I blew out all the holes and fuel lines.
Turned all 4 idle mixture screws out 1/2 turn. Closed the throttle blades completely, and turned the idle screw in 1 1/2 turns.
When I start the moter it will not idle. I can keep it running by opening the primarys on the front carb. When I look into the back carb which is in the idle position, I can see gas dripping from the booster venturi, on the primaries.
If I keep it running off the back carb, the front carb does the same thing.
What is the next move? :rollside:

[Squirtin Thunder]

Call Scott !!!!

[Fiat48]

Here is my progress so far. I took both carbs off, and took all the bowls off. 2 of my float levels were low, corected that problem. 2 of the bowls had small pieces of rubber in them, I blew out all the holes and fuel lines.
Turned all 4 idle mixture screws out 1/2 turn. Closed the throttle blades completely, and turned the idle screw in 1 1/2 turns.
When I start the moter it will not idle. I can keep it running by opening the primarys on the front carb. When I look into the back carb which is in the idle position, I can see gas dripping from the booster venturi, on the primaries.
If I keep it running off the back carb, the front carb does the same thing.
What is the next move? :rollside:
Needles and seats leaking..possibly some junk in there or sometimes you just get bad ones.

[LeE ss13]

Take the metering blocks off and make sure the main body of the carburetor(s) is perfectly flat where the metering block joins it. This can be easily done by laying the long side of a business card up against it. If it is not flat, it will suck fuel through the power valve vacuum chamber from the near by fuel passages. The excess fuel will make the low speed rich and the idle bad not to mention mess up how the power valves work. You can file the body flat again with a standard mill file.
I once installed a small vacuum tube into the Power Valve cambers of two 6109s so I could attach a gauge and read vacuum levels at different speeds. it was on a 11/1 427 flatbottom with 18 gears. The engine held 10 inches of vacuum up to 5000 rpm. Just a thought.

[Moneypitt]

Those carbs are junk............PM me for where to send them so they can be recycled................MP

[texas-19]

I've got 2 750 also.Here is my experience with them.Found out to get them to idle good i had to turn idle mixture screws out 2 turns.Would not idle good even at 1 1/2 turns.Now when engine is cold it idles perfect,hot too.
Try to close the throttle plates and open about 1/2 turn off seats, turn the idle mixtures out 2 turns on all corners,i though this would be too much but engine is happy. If that don't stop the venturi from dripping gas replace the needle and seat.You could also try to run without the power valves just to get it lined out,one less thing to troubleshoot.Mine runs fat no matter what jets i put in it.I put a EGT on it and have tried all different jet combos.
They are a pain but you will like it when you get it right.
Works for me anyway.

[skeepwerkzaz]

If this is a new setup for you then I would be looking for a vacuum leak. Maybe you got the wrong gaskets and you are sucking unmetered air. You aren't running a rectangle port intake on a oval port head are you? That would cause this problem.
Get your handheld propane torch, and without lighting it, have someone start the engine and you hold the tip of the torch close to the intake/head mounting surface. If you have a leak, the engine will immediately begin to run better.
If you have a vacuum leak, you will never get vacuum operated carbs sitting on a tunnelram to work.
Skeep

[Jeanyus]

I'm pretty sure I don't have any vacuum leaks, in the intake manifold area, I ran this intake with 2 600s and got it to idle.
I have rectangle port heads and rectangle port tunnel ram.
I think I'm done beating my head against the wall, trying to get these used carbs to work.
What carbs should I buy ? I like carbs that sit inline, like 6109s. If I get double pumpers, I have to run spacers ($50-75), or the linkage hits the manifold, and then I would need the sideways linkage ($150).
Should I get 650s or 750s ? Rember I only got 427 cubic inches.
Everyone seems to be running 660s should I go that route?
I had a single top on this tunnel ram with 1 850 and it ran great (but looked gay).
I keep getting beat at the lake, buy a guy running edlebrok, carbs. He tells me to throw away the Holleys and go with the Edlebrocks, I don't really like Eddlebrocks, they look too much like Carter BFDs. But that guys boat runs like a bat out of hell.
Should I try the 850 on this old torker ?
http://www.hotboatpics.com/pics/data/500/5859torker.jpg
Or maybee the 850 on a better intake manifold, like an air gap ?
So many choices.
So far I spent over $1000.00 putting carbs on this boat, and it runs like a terd. Help me !!!!

[oldbuck40]

I'm pretty sure I don't have any vacuum leaks, in the intake manifold area, I ran this intake with 2 600s and got it to idle.
I have rectangle port heads and rectangle port tunnel ram.
I think I'm done beating my head against the wall, trying to get these used carbs to work.
What carbs should I buy ? I like carbs that sit inline, like 6109s. If I get double pumpers, I have to run spacers ($50-75), or the linkage hits the manifold, and then I would need the sideways linkage ($150).
Should I get 650s or 750s ? Rember I only got 427 cubic inches.
Everyone seems to be running 660s should I go that route?
I had a single top on this tunnel ram with 1 850 and it ran great (but looked gay).
I keep getting beat at the lake, buy a guy running edlebrok, carbs. He tells me to throw away the Holleys and go with the Edlebrocks, I don't really like Eddlebrocks, they look too much like Carter BFDs. But that guys boat runs like a bat out of hell.
Should I try the 850 on this old torker ?
http://www.hotboatpics.com/pics/data/500/5859torker.jpg
Or maybee the 850 on a better intake manifold, like an air gap ?
So many choices.
So far I spent over $1000.00 putting carbs on this boat, and it runs like a terd. Help me !!!!jeanyus!!! do yourself a favor when you get the dual carbs running! get rid of the rubber hose! if it blows off the fitting you cant say FIRE fast enough! think about it! just watching out for ya thats all...

[Squirtin Thunder]

Carter BFDs. But that guys boat runs like a bat out of hell.
Should I try the 850 on this old torker ?
No Ron come on down I will help you set it up and make it run.

[steelcomp]

Those carbs are junk............PM me for where to send them so they can be recycled................MP
Yeah, like where...your shop??? :rolleyes:
There's nothing wrong with these.
Did you remove all the needles and seats to make sure they were clean? Did you flush out your gas lines before putting it all back together?? Those rubber lines are going to keep giving you trouble...like I told you. You shouldn't have had to change anything from where those were set up when I sent them to you, except to check the float levels. Both carbs should be 3/4 to 1 turn max. off closed on the throttle plates, otherwise you're getting into the transfer slot. AFR screws 1 1/2 turns. Ditch the 8.5 powervalves and get some 4.5's. Yopu need to idle off both carbs, not one.
I check carbs for flat and usually at least hit them with a flat file before I assemble. These weren't too bad. If you go anywhere with that thing, bring it down here and I'll set them up for you. Don't get frustrated so easily.

[GofastRacer]

Wow been gone for a few days here, man has this been blown out of proportion or what! :D

[GofastRacer]

Those carbs are junk............PM me for where to send them so they can be recycled................MP
You are kidding right, LMAO!.. :D :D I know all carbs are junk BUT!.. :smile:

[steelcomp]

Wow been gone for a few days here, man has this been blown out of proportion or what! :D
Ya think??? :notam:

[GofastRacer]

Ya think??? :notam:
:D :D :D

[Moneypitt]

Sure I'm kidding Art, but you and I both know how to fix the ones people are fed up with........So I was only trying to be helpful and offered to recycle them.........Ray

[GofastRacer]

Sure I'm kidding Art, but you and I both know how to fix the ones people are fed up with........So I was only trying to be helpful and offered to recycle them.........Ray
:D :D

[Jeanyus]

I checked the needles and seats all clean. I assembled the rubber lines blew them out with air and then connected them to the barb on the pressure regulator. I will close down the idle screws 1/2 turn,( I did turn the carbs over and check to see if the idle transfer slots were exposed, they were not) screw out the air fuel screws 1 turn. Kragen has 4.5 power valves on the shelf. I'll get 2 tomorrow. I'm trying to idle off both carbs, but the only way to keep it running is to feather the throttle on 1 or both carbs.
Northern Ca. is a great place to take a vacation. Maybee you are due for a vacation.
Sorry I get frustrated so easy, I have spent a lot of time tyring to get these to work, but no success so far. I'll keep trying. :squiggle:

[78Eliminator]

Needles and seats leaking..possibly some junk in there or sometimes you just get bad ones.
Yeah, the rubber tipped needle/seats right out of the holley package are about a 70% success rate. Inspect them. One other thing which has been known to happen, is the actual floats have holes in them and leak. Take the floats out and hold them under water and see if any bubbles come up. Check fuel pressure too. Might be blowing right by the needle/seats if you are throwing too much pressure at them.
One more thing. I would take the sight plugs out of the bowls and then turn the motor over with the coil disconnected to see if you really are keeping the fuel level where it should be. Ground your coil wire way the hell out of the way of the carbs and where the fuel might leak out.

[Squirtin Thunder]

I checked the needles and seats all clean. I assembled the rubber lines blew them out with air and then connected them to the barb on the pressure regulator. I will close down the idle screws 1/2 turn,( I did turn the carbs over and check to see if the idle transfer slots were exposed, they were not) screw out the air fuel screws 1 turn. Kragen has 4.5 power valves on the shelf. I'll get 2 tomorrow. I'm trying to idle off both carbs, but the only way to keep it running is to feather the throttle on 1 or both carbs.
Northern Ca. is a great place to take a vacation. Maybee you are due for a vacation.
Sorry I get frustrated so easy, I have spent a lot of time tyring to get these to work, but no success so far. I'll keep trying. :squiggle:
OK if you have a bunch of Vacume you need BIGGER PVs or it will suck fuel at idel !!!!
#1 vacume reading
#2 two inches down is the PV you start with
#3 I had to move up to 9.5 PVs in a 850DP
#4 With yours Ron I would start with 8.5s
#5 Call me
#6 It is a multy pupose boat :2purples:
I can send you the PVs if you want to try them !!!
5.5 - 9.5
Jim

[Squirtin Thunder]

http://www2.***boat.com/forums/showthread.php?p=1392240#post1392240post1392240

[Jeanyus]

OK if you have a bunch of Vacume you need BIGGER PVs or it will suck fuel at idel !!!!
#1 vacume reading
#2 two inches down is the PV you start with
#3 I had to move up to 9.5 PVs in a 850DP
#4 With yours Ron I would start with 8.5s
#5 Call me
#6 It is a multy pupose boat :2purples:
I can send you the PVs if you want to try them !!!
5.5 - 9.5
Jim
You want me to take a vacuum reading at an idle, right? I have a few problems with that.
#1 There are no manifold vacuum ports on my manifold, or carbs.
#2 I have been trying to get this thing to Idle since fathers day. It wont idle.
Must have something to do with the gas dripping into the carbs through the booster venturies.
#3 I checked the vacuum with the 600s on it, it was less than 10
#4 it has 8.5 PVs in it now.
#5 I read that whole thread on power valves.
#6 acording to spell check, this is how you spell (VACUUM) J/K ;)
#7 thanks to everyone who has tried to help me.
#8 I have to go now, Elvis is knocking on the front door, and a flying saucer is landing on my lawn, or these carbs are driving me nuts.

[ttmott]

Had to bring this post back. I know exactly what is happening; it is a common problem.
In the side mounted float bowls the small floats will not put enough pressure on the needle and seat assembly to stop flow in certain situations. If you have a needle and seat assembly greater than 0.097 (the size is stamped on the flat where the adjusting nut goes over) the fuel pressure needs to be lowered to around 5 psig otherwise the pressure is pushing the float down and filling the bowl up until it overflows from the venturies. There is no need to run a seat orifice larger than 0.097 for gas anyway. Also make sure the needle tips are viton rubber and not metal.
The trade-off is a high flow fuel system with low pressure or a cheapo restricted fuel system that needs to run at 7 or 8 PSIG to keep the bowl full (the holley regulator that comes with their red/blue/black electric pumps is the latter for example).
Keep your needle / seat assembly small and fuel pressures low with the side mounted holley float bowls.
Tom