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John Deere 345 gas running out over flow like float stuck

#1

B

bjones

Noticed gas coming out carb float overflow?? rubber hose from carb. that I assume was from stuck float. It would just drip a few drops nothing major for several months but mower ran fine and then it increased to the point where it wouldn't run, flooding. I assumed float was sticking. Took it to a LMower shop and guy removed carb to clean and he said carb was in bad repair from sometime in past (I bought it used)so ordered a new carb and installed. Still leaks small amount and will run but cut off after a few minutes, guy said it was like it was getting to much gas. Can cut the fuel shut off valve off and will run OK until all gas is gone from carb. Would it be necessary to set float on a new carb? Guy still trying to figure out the problem. Any suggestions, thanks.


#2

Mower King

Mower King

bjones said:
Noticed gas coming out carb float overflow?? rubber hose from carb. that I assume was from stuck float. It would just drip a few drops nothing major for several months but mower ran fine and then it increased to the point where it wouldn't run, flooding. I assumed float was sticking. Took it to a LMower shop and guy removed carb to clean and he said carb was in bad repair from sometime in past (I bought it used)so ordered a new carb and installed. Still leaks small amount and will run but cut off after a few minutes, guy said it was like it was getting to much gas. Can cut the fuel shut off valve off and will run OK until all gas is gone from carb. Would it be necessary to set float on a new carb? Guy still trying to figure out the problem. Any suggestions, thanks.
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As far as the float setting, it would depend on what type of carb it is but, 99% of todays mower carbs, the floats are in a fixed position , so there is no float adjustment. A new O.E.M. carb is the way to go and not an "internet special"......most of the time!


#3

B

bjones

This was not OEM, guy ordered it for like 50.00. U think the new carb is junk and would OEM solve the problem? Thanks for reply


#4

Scrubcadet10

Scrubcadet10

Is your gas tank clean? New fuel filter? Fuel lines clean?
I wonder if trash is getting in the carb and preventing the needle from fully closing.


#5

B

bjones

Yea the tank is clean, all new lines and filter short time ago. Had carb cleaned about yr ago and guy initially thought trash in carb causing the gas to pour out overflow but when he removed carb he said it was clean, no trash. Wonder if new carb is bad, as I said it isn't oem?


#6

Hammermechanicman

Hammermechanicman

The 345's are bad for fuel dripping out of the fuel pump vent. JD issues a new pump with a hose to route the fuel away from the muffler area because of fires. Remove the carb and flip it upside down and pressurize to 10 PSI and see if it holds pressure. If it does probably nit rhe carb leaking. Might try replacing the fuel pump with new style and see what happens. Since fuel pump is near carb folks sometimes mistake leak as coming from carb and not fuel pump.


#7

Mower King

Mower King

bjones said:
Yea the tank is clean, all new lines and filter short time ago. Had carb cleaned about yr ago and guy initially thought trash in carb causing the gas to pour out overflow but when he removed carb he said it was clean, no trash. Wonder if new carb is bad, as I said it isn't oem?
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There is one thing about a carburetor, it only uses what's put through it. You can clean a carb and its just like new, put it on, and pour gas with water or trash in the tank and...WHAM, you got a carb problem all over again before you even try to start it.


#8

B

bjones

Hammermechanicman said:
The 345's are bad for fuel dripping out of the fuel pump vent. JD issues a new pump with a hose to route the fuel away from the muffler area because of fires. Remove the carb and flip it upside down and pressurize to 10 PSI and see if it holds pressure. If it does probably nit rhe carb leaking. Might try replacing the fuel pump with new style and see what happens. Since fuel pump is near carb folks sometimes mistake leak as coming from carb and not fuel pump.
Click to expand...
Hammermechanicman said:
The 345's are bad for fuel dripping out of the fuel pump vent. JD issues a new pump with a hose to route the fuel away from the muffler area because of fires. Remove the carb and flip it upside down and pressurize to 10 PSI and see if it holds pressure. If it does probably nit rhe carb leaking. Might try replacing the fuel pump with new style and see what happens. Since fuel pump is near carb folks sometimes mistake leak as coming from carb and not fuel pump.
Click to expand...

I am sure the gas is coming from the port off of the carb. Has a small black rubber gas line hose coming off the carb and routed down under front of engine that I think is from the float bypass.


#9

B

bjones

mower king said:
There is one thing about a carburetor, it only uses what's put through it. You can clean a carb and its just like new, put it on, and pour gas with water or trash in the tank and...WHAM, you got a carb problem all over again before you even try to start it.
Click to expand...
I agree but old carb was clean per the guy that is working on it.


#10

B

bjones

Went and picked up mower and guy couldn't figure it out. Mower will crank up and run Ok for a bit and cut off and gas still present at overflow line from float, I assume. Question: To eliminate the fuel pump being the issue, can I disconnect the fuel line just downstream of the fuel filter and run a line to a temporary jug or can and if mower runs OK this would indicate bad fuel pump. Will this theory work or does the fuel pump provide some needed pressure that the gravity flow wouldn't provide. Fuel pump from Amazon is only $18.00. Is my plan flawed? Thanks guys for the help.


#11

B

bertsmobile1

A bad fuel pump or bad fuel lines.
Overtime some of the solvents in modern fuel can cause the inner fuel line to soften or crumble.
You don't need much in the way of crud to hold the needle valve open.


#12

Mower King

Mower King

bjones said:
Went and picked up mower and guy couldn't figure it out. Mower will crank up and run Ok for a bit and cut off and gas still present at overflow line from float, I assume. Question: To eliminate the fuel pump being the issue, can I disconnect the fuel line just downstream of the fuel filter and run a line to a temporary jug or can and if mower runs OK this would indicate bad fuel pump. Will this theory work or does the fuel pump provide some needed pressure that the gravity flow wouldn't provide. Fuel pump from Amazon is only $18.00. Is my plan flawed? Thanks guys for the help.
Click to expand...
First, gravity will flow fuel to the carb, if the fuel tank outlet is above the level of the carb. Second, the carb float / needle & seat should stop the fuel in the carb bowl when in gets full (if working correctly and / or don't have a piece of trash in the seat letting fuel bye) no matter if it's gravity or pumped (with a pulse pump.....an Electric pump with a carb, is a different story). Third, take a GOOD close-up pic of this carb, with this "overflow line from the float" and post it!


#13

B

bjones

mower king said:
First, gravity will flow fuel to the carb, if the fuel tank outlet is above the level of the carb. Second, the carb float / needle & seat should stop the fuel in the carb bowl when in gets full (if working correctly and / or don't have a piece of trash in the seat letting fuel bye) no matter if it's gravity or pumped (with a pulse pump.....an Electric pump with a carb, is a different story). Third, take a GOOD close-up pic of this carb, with this "overflow line from the float" and post it!
Click to expand...
Tried to upload pick and attach a file of carb but kept getting message file to big so no go with pick. I did take the open end of overflow rubber gas line and tried to blow through it and nothing but put suction on it and got flow and could hear gas being sloshed around in carb bowl, don't know if that is signification or not. Got it to crank and turned off gas supply valve and it ran pretty smooth for a bit and didn't cut of and would run until gas in carb is gone. I am leaning toward fuel pump, again very cheap so will prob replace and see what happens. Thank you guys for help, I,ll report back.


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