Holley Carb guys, I need help

[Donziweasel]

By switching to the Holley 4150 600cfm carb from the Edelbrock, I finally got the bog in my mid-range out. Another problem has surfaced and while I have worked on Edelbrock, I have never messed with a Holley. The engine is VERY strong, but I finally got to run her for a few hours today and ran into a small problem. The boat for the first hour had a great hole shot and from 30-50 was amazing. The second hour I ran it, it started to pop and sputter some on the low end. It also died a couple of time when I was running above 45 mph and backed off the throttle slowly or quickly into nuetral. When I would try and get on a plane, it would hesitate, pop, sputter, and then start planing. It felt as though it had half it's power till it was half way through the mid range. I am so close to having this boat perfect, I just need to fix this problem. Any help would be much appreciated.

I have decided to go from a 1.47 to 1 to a 1.62 to 1 gear in the drive. The boat is running 53mph @4300 RPM's at 7000ft above sea level (the other day I got 56 @ 4500, but only had 4 gallons of fuel and a 25 mph tail wind). This motor is good for 5000 rpm's. I feel that by dropping a gear and running a 21 pitch, I should get close to 4800 and maybe even pick up a few MPH on the top end.

Lastly, anyone want an Edelbrock 600 cfm marine carb used only twice? I even have a jet, metering rod and spring kit for it. Carb is fine, just did not work for my setup.

[MOP]

I can only guess at the power valve screwing up, Buizilla is a wiz on the Holley.

[smokediver]

before you change the ratio , try a prop that is 2" less in pitch and has a little less in diameter . ie a laser 2 versus a mirage plus . i think in the long run , you are gonna toast that upper gear set . i know that some 350 mags run that ratio but i think you are putting out more power than 300 horse... with a prop less in diameter and pitch you will pick up the rpm's you are looking for plus , at lower alt. you will probably turn at least a 21 , maybe a 23 with your current set up ... my 2 cents ...

[wagspe208]

Any black smoke out the exhaust? Take off the air cleaner and see if it is dumping fuel down the carb. It is possible you got some crap in the needle and seat. Mixing up fuel tank, etc. Check fuel filter condition. What kind of fuel pump are you using? What is the fuel pressure?
Wags

[Donziweasel]

I am not sure I am over 300 hp. Sea level would probably be 325, but not up here. While in it's current set up, it is running 7 mph faster than stock, the motor feels MUCH stronger, especially in the mid and high end. I have never been in a boat that went from 30 to 50 so fast. How sweet it is!

I did not see any black smoke, but I really wasn't looking. Engine did not back fire so much as pop. Not quite as dramatic as a full on "back fire". It also sputtered and lugged off the line. It actaully jumped off the line faster than it ever has this first hour. It was running perfect, but the biggest improvement was still the mid and top.

Buizilla, any advice?

[BUIZILLA]

float level or vacuum leak

[Donziweasel]

Will check both. Thanks. BTW, fuel was fine, pumped 20 gallons in her today before I went out. Which would be more prone to get worse over an hour of running?

[mrfixxall]

DonziW, vacume secondaries or mechanical? Also did you put the lifter valley baffel in? if not the hot oil will boil the fuel whan it gets hot and give you a crummy holeshot and make the engine pop and bang..open the carb throttle blades up and look at the bottom of the intake, if theirs a brownish or burned spot in the intake plenum then its boiling the gas..

[wagspe208]

Sticking float/needle and seat would be most likely. Unless you made MAJOR changes, performance shouldn't change.
Double check timing to make sure it didn't move.
Vacuum leak would cause eratic idle, slow to come back to idle rpm's, especially no load.
Wags

[Donziweasel]

Mech secondaries. Changes made to engine were Vortec Heads, 4bb carb, 264 Comp cam, intake manifold. Idle is fine, EXCEPT when I initially come off a plane and it died a couple of times.

Buizilla, would dying coming off a plane be more of a float issue or needle issue? It was more like when I got on the throttle hard for a second or two and then backed off it would die.

[BUIZILLA]

one of the float levels is too high

[Cuda]

Is it a newer Holley with power valve protection?

[Donziweasel]

Thanks Buizilla. Last question (for now). I am getting different advice about jetting. Many mechanics think that re-jetting is old school and not necessary with newer carbs. Just wondering if I should re-jet for my altitude or leave it alone. Also wondering if the sea level set up could be compounding the problem I am having. Holley does recommend decreasing one jet size per 2000 ft altitude. That would make three sizes for me.

[BigGrizzly]

Re-jetting is not old school except on ECU controlled injection systems that are set up correctly. Holley is correct.

[mrfixxall]

read your plugs for rejetting, with holly they reccomend that you can only go 4 jet sizes up or down from the jet sizes you have now..power valves and float levels are another issue. put a vacume guage on the engine and ck how mant inches of vacume you have,divide the # by 2 and thats the power valve you need,example if you have 9" of vacume you need a 4.5 power valve.
Holly set their carberators up with a 6.5 power valve which = 13'' of vacume,if this your case then and your only pulling 10'' of vacume it will load the motor up with fuel..

set the float level by removing the brass screw plugs on the side of the carb,put a rag under the holes because fuel may spill out whyle adjusting the floats..start engine theirs a screw and a nut on the front and twards the rear on top of the float bowl loosen the screw and turn the nut,clockwise to decrease float bowl level counter clockwise to increase float bowl level.
good luck.

[Donziweasel]

Checked Float level. Front one was a little low, took a little over 1/4 of a turn. Rear one was fine. Would being a little low on one float cause my low end problems? How do I access jets to see what mains I have? Might try and run her this afternoon.

[mrfixxall]

Checked Float level. Front one was a little low, took a little over 1/4 of a turn. Rear one was fine. Would being a little low on one float cause my low end problems? How do I access jets to see what mains I have? Might try and run her this afternoon.

mabe a little but not likely,,you have to remove the front float bowl and the metering block to get at the jets but before you take it apart you should check your vacume to make sure you have the proper power valve in the carb. the power valve is also in the metering block

[mrfixxall]

some pics to see what your getting to,,try to get the blus gasgets they are reuseable..If you have a hp series it should already have the blue gasgets..!st pic is where the jets are and the back of the power valveside ,2nd pic the other side od the metering block ans the power valve,if you look at the face of the power valve their should be 2 numbers this one theirs a 4 and a 5 = 4.5,3rd pic you know,4th pic ase the reuseable gatgets abd the power valve and two types of squirters,one on the top of pic is a extended one which i like to use,their are also numbers on the front of the squirters the bigger the number the more fuel, you only change thease if you having some kind of a boug..im rumming #37 in mine you probebly have 26 in yours,5th pic is just to give you a idea on how much you can do with a holly carb,differant size accelator pump cams bigger cc acceterator pumpc ect..

now that i have you confused
good luck and hope this helps a little.

o also make sure you put the gasget on the rite way on the jet side of the metering block,you can block off the accelerator pump hole, it must be open..

[CHACHI]

Checked Float level. Front one was a little low, took a little over 1/4 of a turn. Rear one was fine. Would being a little low on one float cause my low end problems? How do I access jets to see what mains I have? Might try and run her this afternoon.
If the marine carb is like the automotive carb, remove the 4 screws holding on the front float bowl and the jets are right there in the metering block. A stubby blade screwdriver is all that is needed to remove them. Jet size is stamped on the side.
Ken

[Donziweasel]

Checked for vacuum leaks and it seems well sealed around carb and intake. Talk to me a little about power valves. What do they do, and if they are causing my problem, how do I fix it? I am beginning to like the Holley, just very different from Edel. Another question, could not re-jetting for altitude be creating a super rich condition in the low end? Still planning to run this afternoon.

BTW, Edel is sold, enjoy Barry!

[mrfixxall]

Checked for vacuum leaks and it seems well sealed around carb and intake. Talk to me a little about power valves. What do they do, and if they are causing my problem, how do I fix it? I am beginning to like the Holley, just very different from Edel. Another question, could not re-jetting for altitude be creating a super rich condition in the low end? Still planning to run this afternoon.
BTW, Edel is sold, enjoy Barry!

you got mail!

[RickSE]

I think it's your jetting. I rejetted the secondaries and left the primaries alone on my 4150 for Powell. Since you're at a much higher elevation you'll probably need to re-jet the primaries and secondaries. Rejetting also cleaned up the transon on my boat, min. soot.

Also, pull one of the four lower corner bowl screws all the way out first to drain the bowls before you try to pull the bowl off.

The 4150 in my Camaro will not even idle at 7000' elevation with the low elevation jetting, way too rich. I think you're right and you're loading it up at idle and low speed and also when you pull back on the throttle after higher RPM's.

Aren't you supposed to be in meetings? :wink:

I'm on my way to Powell in the morning. FarmerTX is already there and Don should be on his way.

[Donziweasel]

Rick, thanks for the heads up. I am going to re-jet simply to see if there are any performance gains. Hopefully will cure the problem as well. When are you leaving for Powell? You know you guys are killing me as Powell is my favorite place on earth. I especially wanted to see Don run his boat. I here it is wicked fast. Any plans for a fall trip, even if it is just you? Might be entering due diligence next week on the company so the fall might be good for me.

[RickSE]

I'm leaving in the morning.

You know, I've got a full Holley jet kit down here. Can't you do the meetings over the phone? :tongue: Just messing with ya, I know you're tied up.

Yes, I'll be on Powell until October. Hopefully once a month if I can afford the gas. We usually go more in late summer early fall, late Aug., Sept & early Oct.

You should pick up a little power by leaning it out, just don't go too lean.

[Stevo440]

Was this problem happening the day you had 4 gallons of gas and a 25 mph tail wind??????

[Donziweasel]

No, it did not happen that day as I only ran the boat for 5 minutes. A couple of minutes to warm her up then a WOT run. It only did it after running for about an hour yesterday. Heading out to run her right now.

Rick, you guys have fun and be safe. Last week in Aug or 1st week in Sept might work. BTW, how many are going? I bet I could get 58 mph at Powell. Damn your killing me!:bonk:

[Donziweasel]

Just got back from the lake. Had a couple of hours of diagnosis. Boat once again ran great mid and up top. If you are at a dead stop and throw the throttle WOT to get on a plane, it pops, wheezes, and almost dies. Sometimes you have to come all the way back to nuetral, because it will not rev. If you go slowly to WOT, it hesitates some, but does not pop and will get on a plane, still not at full power though. Then 2500 comes and away she goes! No vacuum leaks and float levels are fine.

Once again, 53 GPs At 4300. More to be had after a little propping.

One thing, I have been running mid grade octane fuel. Should I bump up to High Octane? Engine ran great before mods on mid .

[Cuda]

If it's an older Holley that doesn't have the power valve protectors that are built in now, the first time it backfires it will blow the power valve. Right now I don't remember if that makes them run rich or lean. Damn CRS. :(

I carry three sets of pv's for my Formula.

[RedDog]

... If you are at a dead stop and throw the throttle WOT to get on a plane, it pops, wheezes, and almost dies...

For what its worth and depending on your power and drive - that is a good way to eliminate your carb problems - of course then you have a blown drive to deal with :bonk:

[MOP]

Joe they modify the old ones for the better valves now, Jim can probably fill us in on how!

Phil

[mrfixxall]

with the engine off back off your idle screw all the way,then turn it in just till the throttle blades start to open...turn your air bleeder screws in all the way then turn them out 3/4 turn.if the air bleed screws are turned out more then 1 turn then it will hesitate..if the idle is turned up to high the carb wont be in the idle circuit and the air bleed screws wont do jack..all it takes is .020 gap between the throttle blade and the base plate of the carb then this is where the power valve starts dumping fuel to the jets once the engine starts loosing vacume..remember earlier when i mentioned the squirters in the throat of the carb,,you go to a bigger one if it stumples off the hole shot..theirs a whole lot to it if you want it rite..Holly makes a conversion kit for power valve protection..you have to drill a little hole in the base plate of the carb and install a tiny brass bushing

[Cuda]

Joe they modify the old ones for the better valves now, Jim can probably fill us in on how!
Phil
Yes, I've seen them, that's why I asked. I know neither carb on my Formula have the pv protection. If it backfires, you can be quite confident it blew a power valve.

[Donziweasel]

Carb is a 4150. Not sure how old the design is, but carb was new out of the box.

[BUIZILLA]

I don't think it's a PV problem, you already stated it starts right back up and idles fine..

[Donziweasel]

Reddog, I never run my boat that hard usually. It only take 1/2 throttle to plane but as I was diagnosing a problem, I wanted as much engine input as I could get, so I tried many different throttle positions to get a full understanding of the problem. Don't want to blow a drive, I assure you.

After speaking with a few Holley guys and checking some troubleshooting websites, I have come up with two possibilities. Since the float level is fine and no vacuum leaks, then here is what I have-

1. Although not as likely as the next solution, it is possible Mike is right and the idle is set too lean. This would create a hesitation and bog, as well dying when coming off hard throttle.

2. I am leaning towards this one. When hard off the line, I am getting a momentary lean condition when going from idle to the main metering system. By getting an accelerator pump tuning kit, I should be able to play with cam arms, and more importantly, pump shooter size.

Does anyone have an issue with this logic? Also, contacted Holley and every carb produced since 1992 has a 100% effective power valve blow out system.

Maybe it is a combination of both. Reseted idle mixture and getting a accelerator pump tuning kit. Only problem now is that I have the in-laws coming into town and won't be able to run the boat for a few weeks.:mad:

[mrfixxall]

Reddog, I never run my boat that hard usually. It only take 1/2 throttle to plane but as I was diagnosing a problem, I wanted as much engine input as I could get, so I tried many different throttle positions to get a full understanding of the problem. Don't want to blow a drive, I assure you.
After speaking with a few Holley guys and checking some troubleshooting websites, I have come up with two possibilities. Since the float level is fine and no vacuum leaks, then here is what I have-
1. Although not as likely as the next solution, it is possible Mike is right and the idle is set too lean. This would create a hesitation and bog, as well dying when coming off hard throttle.
2. I am leaning towards this one. When hard off the line, I am getting a momentary lean condition when going from idle to the main metering system. By getting an accelerator pump tuning kit, I should be able to play with cam arms, and more importantly, pump shooter size.
Does anyone have an issue with this logic? Also, contacted Holley and every carb produced since 1992 has a 100% effective power valve blow out system.
Maybe it is a combination of both. Reseted idle mixture and getting a accelerator pump tuning kit. Only problem now is that I have the in-laws coming into town and won't be able to run the boat for a few weeks.:mad:

Donzi w, before you buy a 50 cc accelerator pump try putting a bigger squirter (with the extended tube on it like in the pic i posted)in the throat of the carb..Its held in by a phillips screw and theirs a little rounf gasget under it that wil fall into the throttle blades..try a # 36,this should take care of the stumble..

[Donziweasel]

Ran into a small problem that might be affecting boat. When on the lake yesterday I noticed that the volt meter was only at 11.5 on the dash. Boat was running fine and voltage was not dropping so I figured it was the gauge. Just got it back to my shop and put a meter on the battery and alternator. Getting 12.06 at battery. Checked Alternator. On one post getting 26 volts. On another 12.06. Then I found a larger orange wire with a rubber cup on it. The fitting in the cup was broken off. This wire was larger gauge than any of the others and just hanging out by the alternator. Any idea which post it goes to (if any) and if this is affecting my Voltage? As far as the low end issue, the only thing I could think of is that maybe the fuel pump is not getting enough voltage creating low fuel pressure or somehow messing with the electric choke.

[Donziweasel]

Found the broken eye on a post, reconnected and now have 13.5 at the battery. Not sure how long it has been this way, but fixed now.

[wagspe208]

Weak ignition will ceretaily cause run issues. Low voltage will cause weak ignition. What ign do you have? MSD's are more sensitive. All ignitions need good grounds and power wires. Read into this GOOD GROUNDS AND POWER WIRES. Sorry, pet peeve.
I also would lend to accelerator pump problems. To be sure...accelerate more slowly..ie open throtte blades slower...don't slam them open. If when opening slowly it is still running crappy, keep looking. It should be worse when slamming throttle open than easing throttle open if it is accelerator pump, cam, etc.

Part that has me is that it ran fine for an hour or so...I would not lean toward jetting, acc pump, cam, etc if it ran ok for a while and you didn't change anything.
Wags
PS..these problems can be frustrating. Keep trying, giving feedback, and you will get there.

[Cuda]

Carb is a 4150. Not sure how old the design is, but carb was new out of the box.
I'm sure it will have the pv protection.

[Cuda]

I think you have found the problem. Low voltage will cause an engine to miss, especially under a load.

I think Holley has two accelerator pumps huge , and huger.:eek!:

[Donziweasel]

It has a thunderbolt V ignition (probably going to upgrade on day). I do not think the low voltage was messing with it. It never got below 12 at the battery.

Spoke to some very experienced board members on the phone yesterday. Everyone seemed to think I was going in the right direction with going 4 sizes bigger on the pump nozzle to start with. Ordered a accelerator pump tuning kit with pump nozzles, cams, etc... for $112.00 and a jet kit. Both will be here Monday.

Cuda, I am going to run the boat this morning and see if the voltage has anything to do with it.

I would like to say when I was at the lake yesterday, it was one of those days you dream about. The entire 25 miles lake was smooth as glass, not a cloud in the sky, the air temp was 91, the water 71 degrees, I was surrounded by 10,000 ft snow capped mountains, and counted 6 boats on the whole lake. The lake has a natural hot spring in it you can only get to by boat and as I sat in it looking at the mountains relaxing, I realized how lucky I was to have my boat and be able to spend a quiet (until I crank up my NON muffled engine:wink:) relaxing day on such a kick ass lake. Damn, life is good!:):):)

I do think if I ever get my boat running completely right I will need therapy as it has never really run right (do to my tinkering). I wouldn't know what to do with myself if all I had to do was tow it to the lake and ride around in it.:bonk::bonk::bonk: Maybe I will buy an 18 and mess up the engine so I will have something to stress about.:bonk::bonk::bonk:

[BUIZILLA]

i'm trying to understand how changing the accel pump and squirters is going to cure stalling coming off a plane, when REDUCING the throttle position... help me with this, i'm a little slow learner....

[Donziweasel]

Jim, even if you are a slow learner, you still know 1000 times more than me:) Even Jamie (Rootsy) said you were one of the best Holley (and engine) guys out there and I put a lot of stock in what he says.

I guess I did not do a very good job on that part of the symptoms. After running it again yesterday, and the day before, here is a more detailed description of what happens coming off throttle. It doesn't really die coming off a plane. It is when I throw the throttle down quickly and then bring it back fast. For example, yesterday was showing off a little (why not?) for some freinds of mine, was running around 25-30, went into a super tight turn and was pumping the throttle some from just in gear to 3/4 or so and back to nuetral throughout the turn (my 16 in a turn that tight skips a little on the keel, so throttle input is key). After one big pump and back to nuetral it died. So, it is basically a symptom of hard on and off the throttle very quickly that make it want to die.

[BUIZILLA]

was running around 25-30, went into a super tight turn and was pumping the throttle some from just in gear to 3/4 or so and back to nuetral throughout the turn (my 16 in a turn that tight skips a little on the keel, so throttle input is key). After one big pump and back to nuetral it died. So, it is basically a symptom of hard on and off the throttle very quickly that make it want to die. that's not normal operation, and I seriously doubt you'll tune that out using a carb.... too much going on, that the engine can't absorb chunky droplet fuel distribution vs. load/unload, operating the throttle like that...

[Donziweasel]

I figured as much. I don't usually run my boat that way by any means, but I while I was showing off, I was also trying different things to get a good diagnosis on the problem. My main concern is the stumbling, popping and hesitation on the low end. When you do pump the throttle quickly, I am sure it is compounding the problem, because for a split second you have the problem, then throttle back to nuetral before it has time to "catch up". I am hoping by solving the first problem, it might help a little on the other.

[BUIZILLA]

what carb # is it ?? I don't see where you stated that...

does it have changeable air bleeds in the throats?

[Donziweasel]

Carb is a 4150 marine. Here is a link to the info-

http://www.holley.com/0-80559.asp

and the tech info-

http://www.holley.com/data/Products/Technical/199R7923-2.pdf

Not sure if it has changeable air bleeds in the throats. Thanks for the help Buizilla, I owe you.

[BUIZILLA]

DW, email me direct, or contact me on .ORG on this issue.

thanx

[Donziweasel]

Got my accel pump tuning kit and jet kit today. Heading to the lake to try and do some tuning. Thanks for all the advice everyone, will let you know results tonight.

[tehall]

Interesting thread here....


One point to make.

Each time you are rolling in and out of the throttle, you are dumping between 30 and 60 cc of raw fuel into the airstream.

This can cause flooding in this situation.

The point has been made before if it is a 'bog' it is usually from a lean condition.

On a vacuum secondary carb, this requires a different plan of action, mostly involving the secondary diaphram spring.

It is "possible" you may need to also lean out the shooters at your altitude. Hard to tell from here though :wink:

good luck with it.

[sctiberio]

Donzi W,

Did You Solve The Problem? I Have A Similar Problem With My 91 Sweet 16. Around 1100 Rpm It Will Hesitate, Usually Not Much, But Noticible. It Worsened Tremendously Recently When I Ran The Gas Almost Completely Dry. So I Figured It Had Something To Do With The Gas.

[Donziweasel]

Not sure what happened with mine. I have it running right now. I am at 7000 ft, so I was thinking a problem with the carb running rich or lean. I eventually changed the gear in my drive to 1.65. Somehow the cam and other work I did changed the torque curve of the engine. I put the carb back to stock, and then fattened up the primaries jets one size on the primary jets and accelerator pump shooters. Boat runs great, just need some prop advice which seems to be a little slow coming from the boards. Good luck as I feel your pain after dealing with mine for 9 months.

I just thought of something, a few board members asked me if it did it with a full tank of fuel and an empty tank of fuel. Not sure what could happen in each scenario, but some of these guys know thier stuff and can help.