4 BARREL HOLLEY CARB ADJUSTMENT
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=36467
Printed Date: October-07-2024 at 6:22pm
Topic: 4 BARREL HOLLEY CARB ADJUSTMENT
Posted By: malcolm2
Subject: 4 BARREL HOLLEY CARB ADJUSTMENT
Date Posted: June-24-2015 at 5:30pm
My carb was leaking terribly on my 1st trip out. I bought a "re-new" kit and have gone thru it. I only need to re-install the choke and it will be ready to mount. 1 question: On the main bowl intermediate plate there is an adjustment screw on each side (end). There is a cork seal that fit in the hole and the screw screwed in. So of course that is an adjustment and I tried to figure the number of turns 'til they came out, but it only took 1/2 that many to BOTTOM out when I reassembled. So my question is, how do I adjust these IDLE ADJUSTMENT screws? I want to mount this thing tonight. 1st thought is to put them at what looks to be the 1/2 way point and go from there. How do you know that each one is proper? Since there are 2? Thanks, Clark |
Replies:
Posted By: TRBenj
Date Posted: June-24-2015 at 5:37pm
|
Go gently to the stop (where they bottom out), then bring them 1.5 turns out... That's usually a pretty good starting point. Adjust idle level to ~700-750 and then adjust the 2 idle mixture screws for max vacuum. Then set idle level to 650 or so in gear. |
Posted By: malcolm2
Date Posted: June-24-2015 at 5:42pm
|
I did find a video. Tell me more about the vacuum. Is there a typical port on the SN engine? And what about the CURB adjustment mentioned? %20" rel="nofollow - http://forums.holley.com/entry.php?429-How-To-Adjust-The-Idle-Mixture-On-Holley-Carbs OK I got the curb ? answered with this video..,, holley%20curb%20adjust%20video%20on%20You%20Tube" rel="nofollow - https://www.youtube.com/watch?v=yPe9OsnLzQ8 |
Posted By: GottaSki
Date Posted: June-24-2015 at 5:45pm
|
Tim gots you covered ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: malcolm2
Date Posted: June-24-2015 at 10:44pm
| Test test test..... trying to reply and keep getting ERROR messages. Is something wrong? |
Posted By: TRBenj
Date Posted: June-26-2015 at 9:55am
| Seems to be working for me. |
Posted By: malcolm2
Date Posted: June-26-2015 at 10:36am
|
30 some hours and only 3 posts on the whole forum and they were all 1 sentence.... something was wrong. I tried to email Keith, not sure if he got it, but maybe it is working now. EDIT: yes it is... great. I got the carb back on and the boat started. Seemed to run very rich. Black smoke and water in the driveway. The jets were sounding different and very loud. I could really hear the fuel jetting in. When I shut it down, I could not get it to re-start. During the run I noticed this additional leak. This is a factory seal. The renew parts diagram was very different and had the inlet as an area that could be renewed... not mine. I suppose this bowl or even the carb is done for? Thoughts?  |
Posted By: C-Bass
Date Posted: June-26-2015 at 11:07am
|
Had the same leak when we had our 85. I put JB Weld on it and never looked back. It didn't leak again. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: malcolm2
Date Posted: June-26-2015 at 11:18am
| It looks like the PO originally fixed it with pliers and a good squeeze. I can see some plier marks. I checked and parts can be purchased for this carb. Best I can tell this bowl is about $40. |
Posted By: TRBenj
Date Posted: June-26-2015 at 11:31am
|
Jb weld. If you can't restart after running, check for idle and post-shut down dripping. Going wide open (not pumping!) will clear a flooded condition and allow a restart. Drippin is caused by a leaky needle/seat or a maladjusted or stuck float. |
Posted By: C-Bass
Date Posted: June-26-2015 at 11:45am
|
Not to jump to conclusions, but there seems to be a TON of rebuild kits with leaky needle/seats lately (myself included). So hopefully you didn't throw away your old ones yet. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: malcolm2
Date Posted: June-26-2015 at 12:16pm
| no I am a bit of a pack rat. But check out the picture. There is nothing to adjust or change on the inlet port. It is leaking cause the round metal plate is not sealing the round hole that the arrow is pointing to. As I mentioned that all looks to be pressed in at the factory. |
Posted By: TRBenj
Date Posted: June-26-2015 at 12:26pm
|
C-Bass wrote:Posted By: Bri892001
Date Posted: June-26-2015 at 12:27pm
|
Are you pretty sure it's not just the adapter fitting leaking? If it is, in fact, literally coming from exactly where you left side arrow is pointing, that's part of the bowl casting. The pic almost does look like a crack is there. That may be a situation where you need a new primary bowl, but maybe you could attempt a JB Weld fix first. When you talk about how the fuel inlet setup is different from the rebuild kit instructions, it's probably just because yours is a Marine application. The instructions and books tend to be a little more generic, and may show a picture of a street application. |
Posted By: C-Bass
Date Posted: June-26-2015 at 1:51pm
I guess I need to clarify, my JB weld fix is for the external leak in your picture. You're certainly not the first to have a leak right there. Here is a http://www.correctcraftfan.com/forum/forum_posts.asp?TID=27007" rel="nofollow - link to a discussion on it. The other leak I was mentioning (needle/seat) is a potential cause to your flooding issue and would be inside your carb. You should have gotten a new set with your carb rebuild kit. If the needle & seat don't seal tightly, then your fuel bowl could be continuing to fill up and cause fuel to drip at idle, causing it to run rough. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: malcolm2
Date Posted: June-26-2015 at 2:41pm
|
I saw the JB weld post. I have never had much luck with JB Weld. on the Holley forum a reply thought it was a bad idea, especially on a boat. I don't have a "squirt" at this leak spot, it is more like a weeping. You can see the metal change color and it takes quite a while to even drip. But I can wipe the "wet" color off and watch it appear again. You can kinda see the color change from fuel weeping in the picture. It seems to be accumulating around the casting seam going vertical, just below the arrow. Slightly darker. I did not change anything INSIDE the carb. Can you explain where the "needle seat" is. The first picture of this post is from above, and you can kinda see inside. There are several videos I watched and most of the guys called the large screw in the center of the main ports a "squirter". I did see on the video that the squirter has 2 O-rings, so I am gonna go back and remove the carb and take the squirter out. and check my renew kit for that size o-ring. From the vids I understand that the squirters come in varying sizes for tuning. I am gonna trust that the boat builder or engine designer got that right 15 years ago. |
Posted By: C-Bass
Date Posted: June-26-2015 at 3:57pm
|
Well you're certainly entitled to do what you like, but I would say even a small weeping of fuel is a worse idea than adding some JB Weld to it. If you're against JB Weld, you can wait to see if it seals itself back up again as some others have had happen, or replace the primary fuel bowl. The needle and seat are inside that primary fuel bowl. There are 4 screws that hold the primary bowl onto the carb. When the fuel level inside the bowl is high enough, the float will push the needle up into the seat, and stop the incoming flow of fuel from the fuel pump. In this picture, the needle/seat is what they call "Fuel Inlet Valve"  Google Holley 4160 needle and seat, you will get a lot of pictures/information. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: malcolm2
Date Posted: June-26-2015 at 4:06pm
|
Thanks for the drawing. From the 1st photo, my carb's "needle seat" seal on top of the primary bowl is similar to the inlet seal on the side (that is weeping). Again a metal disk wedged into the bowl case. I did not dismantle the innards of the bowl. I would assume, if the needle seat is serviceable on this carb, it has to be done from the inside. I am not against the JB Weld, I will probably try it so I can to move on to the next issue. Even if it is short term. |
Posted By: C-Bass
Date Posted: June-26-2015 at 4:13pm
|
Yes, marine carbs do not have an external adjustment for the needle & seat, you have to take the bowl off. You'll want a new gasket if you do this. Before you take anything off, follow Tim's advice above and look at the venturi's while idling and after shut-down. These should NOT be dripping fuel in either case. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: Bri892001
Date Posted: June-26-2015 at 4:18pm
|
In summary, it sounds like you are seeing 3 total leaks? 1.) (Exterior) The arrow on the right is the "welch" plug or whatever, that is prone to weeping, but can be fixed with JB Weld. It may clear itself too if it's not too bad. Mine started the season weeping and seems to have stopped. 2.) (Exterior) The arrow on the left, the fuel inlet "fitting." It's pretty rare for these to leak, I'm thinking it could be the adapter fitting. The fuel inlet is part of the bowl, and if it's actually leaking there, I'm not sure how JB Weldable that is. It might require a new bowl. 3.) (Interior) If you are seeing dripping out of the "boosters" going down the primary (front two of the four) barrels. This would be a needle and seat issue most likely. You're not going to fix this with JB Weld. You have to take the bowl off and replace or clean your needle and seat. |
Posted By: malcolm2
Date Posted: June-27-2015 at 1:53am
|
I only have 1 leak that I know of. It only ran for about 2 minutes. So I can't say if there are more. I had just re installed the carb after I "rebuilt" it. Holley calls it RENEW. They say to take it apart and clean it. replace some o-rings and gaskets, etc.... I replaced what I had from the renew kit. But lots of stuff left over, as mentioned. I took the big pieces apart and cleaned the hell out of it. I have a very short video of the attempted restart. I'll see if I can add a link to my you tube video. After the 2 minute run that must have been rich. It will not restart, so I can't look at it while it is running. C-bass you are saying to take the bowl off again. Are you recommending that I disassemble the float? How does that stop a leak? Am I going to be able to pull the inlet valve out thru the inside of the bowl? EDIT: https://youtu.be/4Bg32GJ1gcQ" rel="nofollow - https://youtu.be/4Bg32GJ1gcQ not the best look inside. My wife is pumping the throttle and you can see the jets squirt. Look normal? Next time I get the boat, I will try the WOT, no pumping.... |
Posted By: C-Bass
Date Posted: June-29-2015 at 10:52am
|
So you can't get the boat to start at all now? If it's flooded, pumping the throttle while cranking isn't going to help your cause. Like Tim mentioned above, move the throttle to wide-open, and leave it there while cranking. Don't pump it. The only thing I can see in the video is your accelerator pumps squirting when your wife moves the throttle. This is normal (but also why you don't want to pump the throttle on a flooded engine). Unfortunately, the isn't what we're looking for. You need to have the engine running to look to see if fuel is dripping out of the boosters at IDLE. These are the rings that are right in the middle of the barrels. IF the boosters are leaking, then you would want to pull off the float bowl and clean or replace the needle and seat. I would think there would have been a new needle/seat in your carb renew kit. ------------- Craig 67 SN 73 SN http://www.correctcraftfan.com/diaries/details.asp?ID=6103" rel="nofollow - 99 Sport 85SN |
Posted By: malcolm2
Date Posted: June-30-2015 at 1:39pm
| Yea it won't fire. I am out of town now. I'll try the WOT method next. Carb is off now. I'll see if i can get into the innards of the primary bowl when i return. The kit came with a new power valve. I did not compare to the original. More to come next week. |
Posted By: malcolm2
Date Posted: July-05-2015 at 11:03pm
|
https://youtu.be/qrgg9CeK49Y" rel="nofollow - https://youtu.be/qrgg9CeK49Y anyone know an answer to the above video question? I have the carb on the bench for the second time now. As it turns out I had several pieces that I could have used. I have dismantled both bowls and replaced the "fuel inlet valve and seats". The question above deals with the " pump discharge nozzle gaskets" in the main port. https://youtu.be/9m1PEMP7Wms" rel="nofollow - 4 barrel? NOT this video is asking about the 4 barrel operation. I see no way for the 2 secondary ports to open.... Do they open via engine vacuum? thanks, Clark |
Posted By: Gary S
Date Posted: July-05-2015 at 11:40pm
|
Yes you have a vacuum secondary carb,which you are supposed to have as opposed to a mechanical secondary one. That round cover held down with 4 screws is where the diaphragm that controls it is located . It is not included in the rebuild kit. As to the choke it is opened when voltage it applied to it. Yours is not adjusted correctly. Loosen the screws that hold down the black choke housing and turn it so that the choke plate starts to close. Get a 1/8 drill bit to use as a measuring device. Hold it in the choke area up against where the choke plate would hit if you didn't have it in there. Rotate the black choke housing until the choke plate just touches it and tighten the screws that hold it down. It's now adjusted,when the key is turned on the choke heats up and opens the plate. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: malcolm2
Date Posted: July-06-2015 at 5:27pm
|
So with the carb off of the boat, An electronic choke test might be to put 12volts to the choke terminals and I should begin to see movement? Anyone have time to check out my videos a couple posts up? |
Posted By: Bri892001
Date Posted: July-06-2015 at 10:53pm
|
In your first video, that's the accelerator pump discharge. On the washers, one of them is probably bowled because it took that shape from being in place over time. It's tough to say what the correct washers for sure. Use your best judgement, as long as the tube openings are not blocked by the washer at all. Gary explained on the second video about the secondaries. The only reason the secondaries are connected to the throttle linkage at all is to force them closed when you slow down quickly. They are opened by vacuum, and by the way, you won't get them to open by revving the motor in neutral. The choke, you may just want to set that up, on the boat where you have the benefit of key switched voltage, unless you set up a battery pack or something. |
Posted By: malcolm2
Date Posted: July-06-2015 at 11:16pm
|
Well I tried to contact Holley on the washers. But i think you are right, i just have to go with what i got. I will do the squirter and washers last and wait for an answer. I'll do the JB Weld job and primary bowl jet tonight. I have a 12v drill battery so i rigged it up and watched the bi-metal spring do it's thing. It un winds itself. Tuff to find the tension point to set the cold choke plate point. But i got it. Attached the battery and within a minute it opened. Took the battery loose and in about 5 minutes the plate returned to 1/8". Yee haw something is right! Boring Video link watching the electric choke work. http://youtu.be/rCdOHdA0jxw" rel="nofollow - http://youtu.be/rCdOHdA0jxw |
Posted By: malcolm2
Date Posted: July-08-2015 at 12:14pm
|
Hey, Holley emailed me back and said that the small metal washers, similar to the paper ones that I took off are an upgrade. He said that the top one will deform and take the shape of the counter-sink in the top of the squirter. I decided to JB Weld all 4 of the factory jet seals.... I'll edit with photos soon. So now everything is ready. I was about to go get the boat and do a driveway install and bucket start when I saw a HUGE black cloud. I had 2 hours of daylight left, but it did rain, So the restart will have to be this afternoon. Fingers are crossed! |
Posted By: malcolm2
Date Posted: July-08-2015 at 10:03pm
|
HOT DAMN> The 2nd time is the charm. I re-attached the carb to night. I tried and tried and tried to start it, but nothing. Then I went to find some jumper cables and left the key on and the choke opened up. Hooked the jumper cables to the battery and she fired up. I re-adjusted the pump that is actuated by the throttle. It was too tight and seemed to be mal-adjusted from the PO. So now I will read up on the fine tuning. It is idling alittle low and lumpy. But I am happy as hell that she started. Even the re-starts are quick and responsive. previously it would turn and turn and finally start. I am very happy, thanks to all. If I can't get it smoothed out, I will be back. Clark |
Posted By: Bri892001
Date Posted: July-09-2015 at 1:57am
| Cool man. Good to hear. |
Posted By: malcolm2
Date Posted: July-09-2015 at 11:01am
I can follow this reply, with one exception...... how do I measure manifold vacuum? Best I can tell I don't see any ports on the engine manifold. So I basically left the idle mixture screws on 1-1/2 turns out and set the RPM between 500 and 750 at idle in neutral. I will go to the lake Saturday and tinker with the idle level at the throttle in gear. Where and how do folks measure manifold vacuum? The dash RPM gauge limits the tuning. Is there a better way to measure RPM with no distributor? Thanks, Clark |
Posted By: malcolm2
Date Posted: July-09-2015 at 11:05am
For future reference to folks that wonder about the JB Weld, here is a picture. I did both float bowls.
|
Posted By: Jonny Quest
Date Posted: July-09-2015 at 3:28pm
Manifold vacuum: Find the barb / port at the BOTTOM of the carburetor or on the spacer between the carburetor and the intake manifold. Those ports will provide you with full manifold vacuum. Then hook up a vacuum gauge to the port. Make sure that you have a good seal between port and hose and then between hose and vacuum gauge. NO vacuum leaks. Then you adjust your idle mixture screws in 1/4 turn increments and watch your vacuum gauge. You adjust both screws until you achieve the maximum vacuum reading on the gauge. At this point, some will tell you to turn them back in (clockwise) 1/4 turn for your "final" adjustment. I like to have the boat in gear and at idle. RPMs at 600 to 700 at this point for proper idle mixture screw adjustment using the vacuum gauge. You can do this tied at the dock or on the trailer. I would start at 1 1/2 turns out (counter-clockwise) from LIGHTLY seated. Don't over tighten the screws and damage the seat. When I ran the Holley 4160, my best vacuum was at 1 1/2 turns out. Maybe that's why its a good starting point! Vacuum gauge: I like the unit from Lysle: http://www.oreillyauto.com/site/c/detail/LIS0/20300/N1745.oap?ck=Search_N1745_-1_-1&pt=N1745&ppt=C0103" rel="nofollow - Lysle Vacuum Gauge JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: malcolm2
Date Posted: July-09-2015 at 4:57pm
|
Sorry, but the questions keep coming. I really only see one "barb" and it is much larger than what I saw in a few tuning videos. Is this where you are talking about getting a vacuum from? See photo: 1/2" diameter rubber hose goes from the valve cover vent to the carb riser. 
|
Posted By: Jonny Quest
Date Posted: July-09-2015 at 10:35pm
|
In your photo, you are indicating the PCV hose. That port / barb on the carb spacer will work just fine. Be sure to use the proper size hose. NO vacuum leaks. One of http://www.autozone.com/fittings-and-hose-line-connectors/vacuum-connector-and-tubing/dorman-autograde-1-8-1-4-or-3-8-x-1-8-in-dia-vacuum-tubing-connector/373175_0_0/" rel="nofollow - these will help when dealing with hoses of different sizes. If your PCV hose is in good shape, try removing the PCV valve from the valve cover. Then remove the PCV valve from the hose. Your vacuum gauge can hook-up right up there at the business end of the PCV hose. I put my smaller vacuum gauge hose inside the larger PCV hose. I used a small hose clamp (lightly tightened) to ensure a good seal. JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |