Excessive gas coming out of carbs

reelburner

Cadet
Joined
Apr 28, 2001
Messages
6
Hi,<br />I have a 1970 60HP Johnson outboard. Can anyone tell me why gas is coming out of the carbs when the engine is cranking over. It appears as if the motor is pushing the fuel out instead of drawing it in. Any comments and advice is greatly appreciated. A BIG thank you in advance.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Excessive gas coming out of carbs

Yo, Burner. Does this happen with all carbs or only one? Bent, broken or chipped reeds will cause fuel/air mix to spray out of one carb, but it seems unlikely that two or more cylinders would have that problem at the same time. Several different kinds of carb problems can cause fuel to "overflow" out of the float chamber, but, again, two or more at the same time seems unlikely. Fuel system troubleshooting starts at the tank: properly vented? No excess pressure to or from the fuel pump? No foreign matter interfering with valve operation in fuel pump or carbs? No foreign matter preventing seating of reeds? Reeds in good shape?<br /><br />Good luck and let us know what you learn.<br /><br />JB
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b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
Re: Excessive gas coming out of carbs

tap on the carb bowls, the float could be stuck.............or do a compresion check, cylnders can loose comp in to the carbs...
 

Jersey13

Petty Officer 2nd Class
Joined
Mar 18, 2001
Messages
101
Re: Excessive gas coming out of carbs

reelburner - could you be more specific? I'm not familiar with that motor but possibly if we had a little more info we could help. Where is the gas coming out of the carbs? Have you taken the bowls off to see if the floats are bad (cracked and filled with gas) or corrosion is preventing the needles to seat? These are just possibilities off the top of my head even though it seems unlikely to happen to both carbs at the same time. Keep us posted. These guys on this board are real helpful.<br /><br />-Jersey
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Excessive gas coming out of carbs

Bgagnon has the answer me thinks.<br />If,when you pump the ball,it comes outa the carb(s), it is a stuck float valve needle.<br />Sometimes,gently tapping on the side while pumping,the valve will un-stick. It should be ok after that, provided you got new gas.<br />You may,however, have to tear-down the offending carb, and physically clean the needle.<br /><br /><br />------------------<br />Time to change my tagline
 

csb

Recruit
Joined
Apr 30, 2001
Messages
3
Re: Excessive gas coming out of carbs

just pull the carbs and replace needle valves. Make sure floats float.
 

reelburner

Cadet
Joined
Apr 28, 2001
Messages
6
Re: Excessive gas coming out of carbs

Hello everyone, <br />Wow!, thanks so very much for all your replys regarding my outboard problem. Here's what I can tell all of you so far. At least 1 carb has fuel pouring out of it, and thats the top carb. However, I have encountered yet another problem that stops me from continuing further tests. The motor won't crank over every time I turn the key, in fact, if I turn the key 30 times, it may crank it over one time out of the 30 turns of the key. By the same token, I may turn the key and have it crank over 30 out of 30 times. I've done tests on the ignition switch and there is 12volts to the switch, and the current does transfer to the other terminal when I turn the key. I believe that elimiates the switch. I can bypass the starter relay and have it crank over every time and have don't tests on the relay and again theres 12 volts going to the relay but when I turn the key, there is no power to the other side of the relay where it goes to the starter. Is this the relay or is there another switch, such as a limit switch, that could be the cause of this problem????. Thanks again and sorry for the long long reply.
 

reelburner

Cadet
Joined
Apr 28, 2001
Messages
6
Re: Excessive gas coming out of carbs

Hello everyone, <br />Wow!, thanks so very much for all your replys regarding my outboard problem. Here's what I can tell all of you so far. At least 1 carb has fuel pouring out of it, and thats the top carb. However, I have encountered yet another problem that stops me from continuing further tests. The motor won't crank over every time I turn the key, in fact, if I turn the key 30 times, it may crank it over one time out of the 30 turns of the key. By the same token, I may turn the key and have it crank over 30 out of 30 times. I've done tests on the ignition switch and there is 12volts to the switch, and the current does transfer to the other terminal when I turn the key. I believe that elimiates the switch. I can bypass the starter relay and have it crank over every time and have done tests on the relay and again theres 12 volts going to the relay but when I turn the key, there is no power to the other side of the relay where it goes to the starter. Is this the relay or is there another switch, such as a limit switch, that could be the cause of this problem????. Thanks again and sorry for the long long reply.
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Excessive gas coming out of carbs

Starter problem sound like a bad relay (solenoid,samey-same). What happens, the solenoid takes a low current swithing (ignition switch "start"),and uses it to throw a heavy guage switch (the copper bar inside the solenoid), to switch the starter on and off. These break often on outboards and riding lawnmowers too. The good news is,they are available at auto parts stores in most cases for 12buks or so.<br />And J.B. is right about the reeds. If the motor sat for a long time,it might be varnish hold one open...Then again,it could be a varnished or broken ring,as Bgannon stated. Try some decarb cleaner sprayed into the plug holes,and into the carb..Let sit 20 minutes, and turnover without the pulgs to spit the juice out. Then,run the compression test.<br /><br /><br /><br />------------------<br />the Early bird get's the worm...So, he don't have to stop for bait.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Excessive gas coming out of carbs

Hey, burner. I agree with 12Footer on both the carb (stuck needle valve) and the starter (solenoid) problem. One additional thing you might check: Disconnect, clean thoroughly and reconnect the ground cable (big wire) from the battery where it is bolted to the block. The tin-plated copper cable end is probably bolted with a steel screw through a steel plate into the aluminum/magnesium alloy block. Electrolysis could have corroded the connection enough so that the solenoid pulls in but can't supply enough current to run the starter. Had that happen on a later OMC70 and it gave me fits before I found it.<br />Good Luck.<br />JB
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reelburner

Cadet
Joined
Apr 28, 2001
Messages
6
Re: Excessive gas coming out of carbs

Hi all,<br />Thanks so very much for all the advice. Through all of you I was able to determine the cause of 1 problem, the other appears to have "fixed" itself and remains a mystery as to why it occured at all. That problem was the relay. I had done nothing to it, but its been cranking over ever since. As far as the initial problem, I attribute it to sticky floats and/or dirty float needles. I can tell all of you now that the Johnson appears to be opperational. It still needs to pass the load test to determine weather or not she's ready. I will keep you all informed on its performance. Thank all of you again for your assistance. Because of you, I can now look forward to fishing opener. Thank you again!!!.
 
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