351-W carb?
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=33940
Printed Date: October-07-2024 at 6:27pm
Topic: 351-W carb?
Posted By: nautique74
Subject: 351-W carb?
Date Posted: June-23-2014 at 4:39pm
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I have a 1974 Ski Nautique, what Holley 4-barrel carb came on the 351 Winsor? I'm looking at replacing it with a Edelbrock. Last summer I was having problems with the boat cranking after it ran a while, smelled like gas and wouldn't crank. I tried a tune up; plugs, dist.cap, rotory, points, condinser. A local mechanic said that the seats/seals may not be holding the fuel pressure when it sits a while and letting the gas drip down into the engine, causing it to flood. He also said that Holley's do not rebuild very well and he suggested replacement with a Edelbrock or something else other than Holley. ------------- 1974 Ski Nautique |
Replies:
Posted By: backfoot100
Date Posted: June-23-2014 at 5:49pm
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well Frank, Just some confirmation needed first. The boat starts OK cold and then when you shut it down after warming up good, I assume that it cranks over but doesn't start very easily? Then maybe starts right up after sitting for a period time? Your terminology is confusing. If that's the case, it's a fairly common occurance that can have a couple different fixes. First, start it and warm it up. Remove the flame arrestor and then shut it down. Look down the carb throat right away and see if gas is dripping down onto the throttle plates. I'm guessing it is. If yes, the needle/seat in the float bowl is dirty and not closing completely or the float is adjusted too high in the float bowl and keeping the needle/seat open. Cleaning the needle/seat fixes the first one and adjusting the float down fixes the second. Both scenarios require that the fuel bowl be removed. Holley's rebuild perfectly fine as long as you have a genuine Holley rebuild kit. Anything else is pretty much junk. There have been some quality issues recently with the needle/seats in some rebuild kits but in most instances replacing with the originals has fixed that also. Your mechanic is either too damn lazy or too damn ignorant to fix the problem. I would suggest that you find a new one or we can walk you through fixing it yourself. If you happen to get a new carb, just make sure it's a 600CFM Marine unit. Bolt it on with a new gasket and go. Several here recently have went with a Quick Fuel M600 and have had excellent results. It's a Holley design that is much easier to make adjustments on. Edelbrock makes a good carb with mixed reviews. They're either loved or hated. Hope this helps. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: racingnc
Date Posted: June-24-2014 at 10:26pm
| Want to fix mine backfoot.... |
Posted By: backfoot100
Date Posted: June-25-2014 at 10:32am
Absolutely. Just get it down to FL and I'll fix it right up. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
racingnc wrote:Posted By: Waterdog
Date Posted: June-25-2014 at 1:17pm
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Holley's are simple and easy to understand if you want to learn. There are a kazillion more Holleys than ALL the other carbs out there combined. That being said everything machanical wears out sometime. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: jkilbert
Date Posted: June-25-2014 at 2:59pm
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Holley carbs aren't difficult to rebuild if you take your time with it. Buy high quality kits and try to use the blue. Alcohol resistant gaskets and accelerator pump. If you go to Jegs or Summit Racing you can find a lot more alcohol resistant hardware because of alcohol race cars. ------------- 1979 Ski Nautique |
Posted By: mamigacz
Date Posted: June-25-2014 at 8:32pm
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I'm very curious if this issue gets resolved. I don't have this issue anymore with my efi conversion, but it was extremely annoying before the conversion. I rebuilt the carb and the problem continued I replaced the needle and seat twice and the problem continued I adjusted the floats to spec and problem continued I adjusted the floats lower than spec and the problem continued. I watched for venturi dripping after shutdown (approximately 2 minutes) and noticed nothing. I replaced the coil and the problem continued. The hard start never left me sitting, but it was extremely annoying when someone other than me tried starting the boat. Whats even more troubling is my Camaro has an edelbrock 600cfm carb on it and it has the same issue. |
Posted By: jkilbert
Date Posted: June-25-2014 at 9:05pm
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A lot of the problems now with carbureted engines stem from the gasoline itself. The oil companies have engineered the gas to work better in fuel injected engines. One of the things that has happened is that the new formulations have a lower vapor pressure, meaning that they boil at a lower temp. On fuel injected engines is isn't a problem because you have a feed and return line. Fuel doesn't. End up sitting on a hot engine. It is constantly recirculated back to the tank. Injected engine also operate under pressure usually around 60psi at the rail. In the carb'd engines fuel sits there in the bowls and boils off. This allows more vapor than liquid to move through the carb. Hence....vapor lock is more of a problem. I found this out from a mechanic friend of mine when I was having this issue with the Mopar 440 in my Winnebago. His "cure" on his race car was to use a cold can. That works fine for racing but not practical for boating or the street. ------------- 1979 Ski Nautique |
Posted By: backfoot100
Date Posted: June-26-2014 at 12:57pm
If the fuel wasn't dripping after shutdown you had a different issue. Was the choke fully open when warmed up? ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: mamigacz
Date Posted: June-26-2014 at 1:23pm
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Yep, Its wide open after warm up. The Camaro too. |
Posted By: backfoot100
Date Posted: June-27-2014 at 12:36pm
I guess I would like to know what your definition is for hard start then. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: mamigacz
Date Posted: June-27-2014 at 7:45pm
| Cranking for more than 5 seconds before starting. |
Posted By: lakedog55
Date Posted: June-30-2014 at 1:28am
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I wouldn't use a Eldebrock for an anchor ------------- Lakedog55 |
Posted By: backfoot100
Date Posted: July-01-2014 at 11:43am
So it cranked for more than 5 seconds and then started without touching anything else. Or did you have to pump the throttle, hold it wide open or do anything else with it? ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: GottaSki
Date Posted: July-01-2014 at 12:14pm
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just Crack the throttle before starting. Your pin should already be out anyway, most times. If thats not acceptable, make sure you base timing is at least 10 btdc, no less, and set the idle mix screws to the strongest and smoothest idle possible while in forward gear, not neutral, quite equivelent to the technique with carburated auto trans cars, set idle mix when in drive with wheels chocked. This also often cures an off idle stumble Doing otherwise sets the mix too lean for a clean restart with no throttle. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: nautique74
Date Posted: July-08-2014 at 4:50pm
Correct, but it doesn't matter if it has been sitting a period of time, unless it's the next day. This is kinda of what happens; A. It starts right up at home, run a minute, shut it off and head to the lake. B. 45-minuets later I'm putting it in the water, it turns over but takes a couple of minutes to start. C. I run around on the lake a while, runs great, 30-45 minutes, shut it down to chill awhile. D. Climb back in, 1/2-1-2-3 hours later, it turns over but takes several minutes to even start hitting. It just turns over and over for several minutes then Pup...pup-up...pup....pup-pup-pup..pup-up...pup-pup-pup..boom-boom-boom-varoom with a gasy smell and smoke out the exhaust. I've tried to start it diffrently each time; with no throttle, a little throttle, wide open and everything in between. ------------- 1974 Ski Nautique |
Posted By: SNobsessed
Date Posted: July-08-2014 at 6:21pm
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2 things to check next time you go to the lake: Strength of spark & fuel dripping down into the carb throat. You may even have both problems at the same time. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: lakedog55
Date Posted: July-08-2014 at 9:29pm
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It's funny how great they seem to run on the trailer. ------------- Lakedog55 |
Posted By: lakedog55
Date Posted: July-08-2014 at 9:31pm
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And what else happening in the chill time? points or electronic ignition? ------------- Lakedog55 |
Posted By: nautique74
Date Posted: July-09-2014 at 3:51pm
It has points. The chill time...A dip in the lake and a couple of beers. ------------- 1974 Ski Nautique |
Posted By: nautique74
Date Posted: July-09-2014 at 3:56pm
I'll check this weekend for the gas drip. I changed spark plugs, points, rotary button, condenser & dist.cap about the only thing left is wires & coil. Once it's running it runs great at all speeds, No skips or misses. ------------- 1974 Ski Nautique |
Posted By: lakedog55
Date Posted: July-09-2014 at 11:12pm
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Might as well throw some wires on it. Coil is usually good or bad. I would switch it over to electronic, but that's just me. Starting problem sounds like carb. Fuel drip will cause it to flood. just for giggles drain your bowls. ------------- Lakedog55 |
Posted By: nautique74
Date Posted: July-16-2014 at 11:45am
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I checked for the fuel drip this past weekend. When I take the flame arrestor off the choke valve is blocking my view and when I push it open, gas will squirt in the carb but I don't see any dripping after that. By the way it did start better this weekend, it took a minute but not several minutes. I had topped the gas tank off with high test instead of regular. ------------- 1974 Ski Nautique |
Posted By: Bri892001
Date Posted: July-16-2014 at 12:12pm
Setting Chris, Tom or Eddie up for the Alley-oop  
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Posted By: Bri892001
Date Posted: July-16-2014 at 12:20pm
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Posted By: Bri892001
Date Posted: July-16-2014 at 12:26pm
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Everyone must be too busy doing their actual jobs. I can't wait any more. It sounds like the choke is not opening, or not opening consistently or reliably. If the boat is warmed up, and your choke plate is closed, we'll there's your problem right therrr' |
Posted By: backfoot100
Date Posted: July-16-2014 at 12:43pm
You did test this warm correct? If so, your choke should be open. If the choke wasn't open, it's either misadjusted or it's just plain worn out and needs replacing. If it's not opening, it will start like crap when it's warm. When cold, it should have a 1/16'-1/8" opening gap. Just turn the key on (don't even start the engine) and you should be able to watch the choke open. It'll take about 45 seconds to a minute. It needs to open up completely so it's straight up and down. If it isn't doing that, then you should first verify that you have 12 volts to the choke coil (the round black thing on the side of the of the carb) when you turn the key on. If you do then the choke coil needs to be replaced. Secondly, I have no idea how just pushing the choke plate open would give you a shot of fuel. Or did you manually open the choke plate and then operate the throttle? I'm confused on this. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: Bri892001
Date Posted: July-16-2014 at 12:51pm
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Opening the throttle to full will force the choke open usually. I'm thinking he opened the choke with the throttle and got an accelerator pump shot. |
Posted By: GottaSki
Date Posted: July-16-2014 at 12:53pm
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Yes, we may have a nomenclature issue to address! Lookup Choke plate, throttle plate, accel pump nozzel, and booster nozzzles. errant drips will be from the booster nozzles. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: Bri892001
Date Posted: July-16-2014 at 6:51pm
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I have this book and like it a lot. It may not be the most comprehensive, but it packs most everything the casual user would want to know into a quick, easy read. Pound for pound, it packs a lot of knowledge: http://www.amazon.com/Holly-Carburetor-Handbook-4150-Hp473/dp/0895860473/ref=pd_sim_b_2?ie=UTF8&refRID=04QYYHF8QM84ZB2WDPAR" rel="nofollow - http://www.amazon.com/Holly-Carburetor-Handbook-4150-Hp473/dp/0895860473/ref=pd_sim_b_2?ie=UTF8&refRID=04QYYHF8QM84ZB2WDPAR  I have this DVD too: http://www.amazon.com/Holley-36-378-Carburetor-Installation-Tuning/dp/B000M2AM22/ref=pd_bxgy_b_img_y" rel="nofollow - http://www.amazon.com/Holley-36-378-Carburetor-Installation-Tuning/dp/B000M2AM22/ref=pd_bxgy_b_img_y A lot of what's in the DVD can be found on youtube, but it's nice to have it all packaged together. Plus, on DVD, the whole family can enjoy in the comfort of your living room, haha. |
Posted By: boardersdad
Date Posted: July-16-2014 at 7:24pm
Ok, now that is a PERFECT description of what I experienced last week on the Rochester carb on my pontoon's Mercruiser 140. I mean, exactly that pup...pup-pup... and so forth. However, oddly, in my case it was one morning with the engine cold. After messing with it for a long time (more than an hour), I came to believe that I had a combination of problems. I think I had some dirt in the carb, so I blasted it with more carb cleaner than I care to admit. Then I held the choke plate (which was closed too tightly) wide open with a screwdriver while I cranked it to pull the cleaner through. It started pup...pupping more and more then finally sort of pupped into running and then ran, with that gassy smell and the exhaust smoke, just as you describe. I ran it in neutral a little high on the rpm's, like around 2000 to 2200, for about 20 minutes; don't usually like to do that with no load. Anyway, it smoothed right out and never had the exact problem again... but... later in the trip the engine wasn't happy starting when warm. I've worked on this engine a lot over the years, and it generally starts as soon as I turn the key. But I had to grind for maybe 4 or 5 seconds when warm. I am convinced now that my problem is twofold -- the battery in that boat is 7 years old and isn't throwing her over as fast as it should, so I'll be picking up a new one. And I'm convinced the choke is misbehaving. I converted the Merc 140 over to electric choke about two years ago, so I am going to run through the choke calibration procedure when I find the time. For one thing, I noticed the choke plate is sitting fully closed when it should be cracked open a bit. Anyway, I know this isn't the same carb or engine, but the principles are pretty much universal and your pup...pup description matched exactly, so maybe this will be of some help to you. I hope you find it sooner rather than later! |
Posted By: gR@HaM
Date Posted: July-16-2014 at 8:03pm
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I too would recommend that holley book, not an expensive buy and it gives a good overview of the mechanics ------------- '82 Ski Tique |
Posted By: racingnc
Date Posted: July-16-2014 at 8:43pm
| So I have had the same problem. I just had mine rebuilt the problem with mine was the secondary butterflies were not opening when the engine was at operating temperature to compensate for the choke being open. I also found the rear floats were set high causing gas to drip out of the front jets. The other issue found was a bit of dirt in one of the jets. The boat has NEVER started so AWESOME. Sounds like a new boat starting. Hope this helps. |
Posted By: nautique74
Date Posted: July-17-2014 at 5:00pm
The engine was cold had not ran it in a week. Started right up when I put it in the water. Running great, no skips or sputters. Ran about 45-minutes. Engine was hot, shut it down. I took the breather off. The choke is almost closed (about a 1/16" open). I just pushed the choke valve open with my finger. A little gas squirt, didn't touch throttle. Had to hold the choke open with my finger. No more gas, but when I remove my finger choke valve closes. I'm thinking choke problem. ------------- 1974 Ski Nautique |
Posted By: GottaSki
Date Posted: July-17-2014 at 6:09pm
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yep start with the choke see if it gets power. Then see if its grounded Then see if it has continuity If cant be corrected, loosten and rotate the choke so its open til you get a replacement. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: backfoot100
Date Posted: July-17-2014 at 6:21pm
Definitely the choke. Be warned if you do rotate the choke as Tom instructs, it will make your cold starting horrendous unless you manually hold the choke closed. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: TRBenj
Date Posted: July-17-2014 at 6:33pm
| Meh, my nicest starting boats (warm and cold) have the choke bypassed entirely. |
Posted By: boardersdad
Date Posted: September-09-2014 at 2:35am
I adjusted the electric choke on our '84 SN2001 351W Holley 4160 yesterday--I disabled it. After reading your post, we're going to try going without it. Over the years the choke on my pontoon boat's Mercruiser 140 gave me nothing but trouble, so I'm going to disable that one, too. We'll see how it goes. We don't use the boats for ice fishing during the winter. 
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Posted By: boardersdad
Date Posted: July-02-2015 at 11:27pm
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1984 SN2001 351W Ok, still having trouble with this. Last September the threads that connect the fuel line to the front bowl were leaking and found to be stripped. Found a used bowl with floats and installed it. The float adjustment looked the same as the old bowl but that was just a visual check. After that, the engine won't fire when cold unless we hold the choke plate open. Starts great when warm. Tried disabling the choke but experienced a hesitation on hole shot acceleration, never had that before. Doesn't sound like a choke issue. Now have set choke to 1/16" gap when cold. Still have to hold choke plate open and sometimes use starting fluid when cold. Electric choke opens normally. Not sure if we still have the hesitation; finally getting ready for summer. Thoughts? |
Posted By: 8122pbrainard
Date Posted: July-02-2015 at 11:34pm
Steve, Still leaking at the fuel line fitting into the carb? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: boardersdad
Date Posted: July-02-2015 at 11:41pm
| No more fuel leak. The fuel line wasn't in the best of shape after trying to get the leak to stop last Labor Day weekend. I replaced it with USCG approved soft line with an inline fuel filter, no more filter at the carb inlet. |
Posted By: Bri892001
Date Posted: July-03-2015 at 12:56am
| When you put your new bowl on, did you properly adjust the accelerator pump linkage? If you have any play there, allowing the throttles to open (even a tiny bit) without the acc pump pumping, you could get a hesitation. |
Posted By: boardersdad
Date Posted: July-03-2015 at 2:13am
| No, I didn't know about that. I watched the video tonight from another post. That was new to me. I think I have all the manuals, is that covered in the manual? Not home to look thru it right now. |
Posted By: boardersdad
Date Posted: July-03-2015 at 2:11pm
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I'm going to read up on this and try to adjust it today. Question: could my not adjusting the accelerator pump linkage cause both problems... the poor cold starting (maybe not getting accelerator pump shot when pumping throttle before starting) and the hole shot hesitation? I'm thinking that might make sense. Is there anything else I should've done when replacing the bowl? I used a new gasket. Thanks. |
Posted By: Bri892001
Date Posted: July-04-2015 at 12:02pm
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Adjusting the accelerator pump linkage is super easy. There's a nut and bolt with a spring, and you just unscrew it a little, and that opens it up a little and takes out any slack. The linkage is kind of line a see saw, with one side riding the acc pump cam, any the other side actuating the lever. The lever side has the adjustment. Holley has some great videos on YouTube. The cold starting... not sure on that though, the acc pump lonkage would have to be waaay loose, but anything is possible. |
Posted By: Bri892001
Date Posted: July-04-2015 at 12:04pm
| The only thing is you might need two of the same size combination wrench, which not everyone has laying around. For mine it was two 3/8th. |
Posted By: Jonny Quest
Date Posted: July-04-2015 at 5:26pm
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Good video from Holley on accelerator pump adjustment: https://www.holley.com/blog/post/how_to_adjust_the_accelerator_pump_on_holley_carburetors/" rel="nofollow - Video Link JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: boardersdad
Date Posted: July-05-2015 at 5:00am
Great advice, guys. I studied the videos and we went out to work on it. Pump the throttle--no squirt. Took a close look at the accelerator pump linkage and the threaded end of the bolt was hung up on the barrel housing for the fuel inlet. When my son gave it a tug with his fingers, it released. I shortened the bolt a bit to avoid it hanging up and we adjusted closed throttle and checked WOT 015 feeler gauge per the videos. Cold start now is great. Doesn't seem to hesitate any more but we'll see on the water. Pics below are before and after, posting from my phone so hope it works. Thanks for all the great input! 
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Posted By: Bri892001
Date Posted: July-05-2015 at 10:11am
Looks like you found the problem 
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Posted By: boardersdad
Date Posted: July-08-2015 at 1:04am
| Cold starts great, but still hesitating on the water. I took off about half of the threads showing in the first pic, and as you can see in the second pic, the length of bolt below the linkage is quite a bit longer at this point. So if we tighten the nut to shorten the bolt, as long as we don't get loose play,will that make the accel pump arm move sooner? When watching the linkage, I can see the throttle linkage move just a little before the accel arm begins to move. Plan to adjust this tomorrow, Wednesday. |
Posted By: Jonny Quest
Date Posted: July-08-2015 at 2:24am
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Might be time for an accelerator pump rebuild. You may also try a different size squirter / nozzle. Try going larger by 3 or 4 sizes. If you have a 31, try the 35. That can also solve the bog or hesitation. JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: Bri892001
Date Posted: July-08-2015 at 2:26am
That is likely the problem. Also though, if you have the screw opened up so much, that the actual pump lever is never able to fully return to the full start position, you're not going to get a proper pump shot either. |
Posted By: boardersdad
Date Posted: July-10-2015 at 1:23pm
I think that was it, Brian. Yesterday I had the boy tighten down the nut (shorten the bolt) until the pump lever arm lost contact under the fuel bowl. Then I had him use his fingers to actuate the pump arm, to feel where the resistance of the pump just started--and then to set the bolt head to exactly that amount of stroke, as a starting point. All of this was with the engine warmed to operating temp. Then he took it out on the water and tested it. After each poor result, I had him loosen the nut (lengthen the bolt) a thread at a time. He's got it dialed in pretty darn good now--the hesitation is gone. I was going to have him do the final adjustment a quarter turn at a time, but he thinks he's right on the sweet spot now. I'm not sure how "wide" the sweet spot is in terms of turns of the nut. Thanks to all you guys! You saved a lot of frustration on our vacation. :) Steve |