#1
IP: 207.97.145.115
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Early model Carb gushing fuel!!!
Hey guys, i recently inherited an atomic 4 engine in an Irwin 28 and have recently started having trouble with the old girl. She ran like a dream before winter and then after sitting through an unusually cold New York winter with only a few gallons in the tank and what appears to be a little growth of some sort started running a bit rough( shocker!)... I thought i could just top her off with some premium and hopefully get by for a few days whilst i moved her but no go there..... After running her for the first time with the new fuel i noticed fuel pouring out of the flame arrestor portion of the carb.... i have since torn the carb apart cleaned every part and reassembled every piece meticulously to no avail, fuel still pours out. I realise the tank needs to be emptied and cleaned, ordered a tank siphon today, but shouldn't the float valve needle be closing regardless? Or is the water and little particles enough to stop that from happening? Another words is this just a matter of changing the fuel and cleaning the tank or do i need to get a rebuild kit for the carb? Any help would be greatly appreciated, thanks all!
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#2
IP: 76.122.168.101
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If the flow of gas is not being stopped, I would suspect the needle is not seating properly or the carb float is not floating.
I would start by cleaning the needle and dressing the seat. But it sounds like you have already done that, so my next thought is to inspect the float. Sometimes they develop a pin hole, take on some fuel and fail to close the needle valve (because they no longer float). |
#3
IP: 24.224.152.244
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Quote:
__________________
Mo "Odyssey" 1976 C&C 30 MKI The pessimist complains about the wind. The optimist expects it to change. The realist adjusts the sails. ...Sir William Arthur Ward. |
#4
IP: 173.66.236.200
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Also, you can pull the plug in the base of the carb bowl a drain the gas into a clear glass container. Check it for particles and crud.. It should be clean & clear; otherwise the crud will keep fouling the seat of the needle in the float valve and prevent it from fully closing.
I your the exact symptoms 2 years ago, and my problem turned out to be a leaky float that no longer had enough buoyancy. You could hear the gas slosh in it if you shook it next to your ear. Oh yes, welcome to the forum! You've found a great repository of knowledge here for all things A4.
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@(^.^)@ Ed 1977 Pearson P-323 "Dolce Vita" with rebuilt Atomic-4 |
#5
IP: 24.152.131.153
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I had the exact same symptom with an oddball cause when initially test running my spare engine. After it gushed I took the carb apart and found the float pivot pin out of its hole on one end. I repositioned it, reassembled and restarted the engine. The carb performed fine.
The next day I tried to start her up and the same thing with the same dislodged pin problem. What the Heck?? I later took advantage of another member's generous offer to rebuild this and another spare carb I had. What he found was the pivot pin had been replaced with a home made fabrication of smaller diameter. Could have been wire stock on the shelf, a finishing nail or a paper clip, who knows? I'm glad he was the one rebuilding, can't say I'd have ever noticed.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#6
IP: 142.136.107.234
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seats and hoses
The needle and seat don't care about water in fact it floats better in water as it is heavier!!!! If fuel is flowing something is stuck or the float is full f fluid.
It is most common for a float to act up after R&Ring the fuel lines a couple of time. The sharp barbs and the tugging on the line literally cut out small piece of the hose and those can be a big issue. That is why whenever I do carb work I just replace the lines, especially on someone else's boat. Dave Neptune |
#7
IP: 66.108.25.205
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Suggest you replace your fuel lines asap - if you don't know how old they are. E-gas can eat some of the older hoses allowing lots of particles into the fuel.
You already know you need to clean out your fuel tank. Here is what I found at the bottom of our 20 gallon fuel tank.
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Tartan 27 #328 owner born 1958 A4 and boat are from 1967 |
#8
IP: 66.87.80.177
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Thanks guys! Pumped the old fuel, replaced the fuel filter, replaced spark plugs and wires, and rebuilt the old carb, again. She started stronger than when I bought her! Now I just need to figure out while the raw water discharge is merely a drip! I'll post a new thread...
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#9
IP: 174.94.32.231
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Quote:
Because you have an early model A-4...the cooling water doesn't begin flowing fully through the exhaust until it warms up and the thermostat opens. Late model A-4's cooling water circulation through the exhaust begins immediately upon start up. Don't worry - be happy you have an early model A-4! |
#10
IP: 173.180.205.200
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I had the same thing but I think I have it remedied. However, in the process going over the carb completely I found a plugged breather tube (maybe 16th dia.?) between the manifold to the carb which I blew out and put back but now I'm getting water/crud into the carb and it's bowl. I drained it and tried it but still no go.
I think it's also the fact that I think the manifold got flooded somehow from trying to crank it. My mechanical buddy think (but doesn't know A4's) that there is a hole/crack in the manifold somehow but I don't think so. I got wet plugs etc to be dried out and cranking the engine with the saltwater intake off to do that. Should I keeping this until it runs or? I'm not a neophyte A4 owner as I've had the same boat since '88 through 2 A4's but I'm a little baffled. I tried to work it 2 months ago now and I thought it was fuel or the filter but I've done that but with no success. The electrical (condenser, caps, points etc) have been replaced too and I have spark. |
#11
IP: 99.124.190.130
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ricglobe,
sounds like you may have solved your carb problem? Went through the same thing just yesterday. It's a simple thing - fuel flows into bowl, floats push valve up against seat, valve closes. Problems can be in 3 areas - first, bowl is cracked and fuel leaks out. Second, floats don't due to holes in the float. Third, valve doesn't seal. Solutions a) cracked bowl - replace, b) sinking floats - replace, c) bad valve - replace. Note that solution is same in all cases - just a question of what to replace. Start with the valve and seat - least expensive, and with alcohol fuels, most likely. Cracked bowl should be visibly evident. Floats with a leak - likewise. Fuel leaks in - does fuel leak out?? |
#12
IP: 76.7.148.255
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Orcaspirit. Welcome to the forum. You may do better starting a new thread as your carb seems to be a late model. The 1/16 tube is probably the scavenge tube. It is designed to draw excess fuel from the carb and into the intake half of the manifold. A crack/leak in the manifold, as your friend suggests, could cause your symptoms. Have you pressure tested the manifold?
Dan S/V Marian Claire |
#13
IP: 173.180.205.200
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Quote:
I'll let you know how I make out. |
Tags |
bad gas, early carb, fuel |
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