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John Deere LX188 carb vent overflowing

#1

8

8950LX

Hi all,

I've got an LX188 with the Kawasaki FD501V. I recently noticed after shutdown fuel coming from the bowl vent on the top of the carb. This explains the mystery fuel smell I've had for a few months now. I took the carb apart and it was surprisingly clean inside. The float needle however did show some slight wear on the sides and I suspected maybe it was sticking in the needle bore and not seating properly hence the overflow. So I ordered a carb kit from the dealer, replaced all the components in the kit including a new needle. Fired her back up, warmed her up thoroughly and low and behold it leaked(overflowed) again a few seconds after shutdown. I've checked the vent hole on the fuel cap to make sure it wasn't holding pressure or any sort of vacuum and that seems to be working fine. Is there anything I'm overlooking such as maybe fuel line routing(siphoning effect)? I'm very familiar with carbs of all sorts and I'm starting to think that possibly the seat is simply worn in this carb and maybe I'm due for a replacement carb. Any thoughts or suggestions are greatly appreciated. :cool:

Thanks,
Bill


#2

I

ILENGINE

Something I have done a few time when I had a carb that wouldn't seat the needle, was put a small amount of valve grinding compound on either a Q tip or the tip of the old needle and insert it into the seat and give it a few turns, then clean the seat area out well, and then recheck for sealing of the new needle valve.


#3

8

8950LX

ILENGINE said:
Something I have done a few time when I had a carb that wouldn't seat the needle, was put a small amount of valve grinding compound on either a Q tip or the tip of the old needle and insert it into the seat and give it a few turns, then clean the seat area out well, and then recheck for sealing of the new needle valve.
Click to expand...

Well I tried the valve grinding compound....no luck at all. The original carb clearly had a needle(new & old) that wouldn't seat and vented quite a bit of fuel almost immediately after shutdown. The dealer sold me a new needle but said that a new needle seat wasn't listed. So....... I replaced the old carb with a new Kawasaki #15003-2693 carb per the dealer recommendations. Run the motor for 10-15min and sure enough it starts leaking thru the vent hose again 1-2min after shutdown. Not nearly as bad as the old carb but enough to make a 3" stain on the floor. When it does vent it is only a drip every 20-30sec. If I wipe it on my finger it has a fuel smell to it, evaporates quickly and then leaves absolutely no fuel smell on my hand or fingers. Is it possible this is the ethanol in the E10 fuel boiling off or am I going nuts or both? My wife is on my butt and concerned about this being a fire hazard. Any help or suggestions is greatly appreciated.


#4

BBO

BBO

8950LX said:
I've got an LX188 with the Kawasaki FD501V. I recently noticed after shutdown fuel coming from the bowl vent on the top of the carb.
Click to expand...

I'm not sure which vent you are referring to.
The float/needle valve must be stuck open unless you are referring to the fuel pump vent.
You might need a new fuel pump.
Read this..
345 caught on fire

Either way don't run it until you fix this. :shocked:


#5

F

fireman9513

I have a friend that has the Same problem, ordered carb kit and now it's worse!
The vent comes out the top of the carb body between the throttle shaft and choke shaft with a hose down the side of the carb.
Wish someone knew the answer


#6

BBO

BBO

fireman9513 said:
I have a friend that has the Same problem, ordered carb kit and now it's worse!
Click to expand...

Read this.

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  • LX188_Carburetor_147-150.pdf
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#7

F

fireman9513

BBO said:
Read this.
Click to expand...

Not the same thing, this guys carb is what is leaking


#8

B

bscott157

fireman9513 said:
I have a friend that has the Same problem, ordered carb kit and now it's worse!
The vent comes out the top of the carb body between the throttle shaft and choke shaft with a hose down the side of the carb.
Wish someone knew the answer
Click to expand...

I wish someone knew the answer too. I have the same problem and just had carb adjusted and cleaned last year by a pro service man.


#9

L

lester56

Hi All,
I have the same problem as Bill's with my Simplicity landlord FD501V 17hp.

Quick recount of events:
- 2012 Noticed gas dripping for rubber downward facing tube a few minutes after shut down. (Bubbles out... almost like it is boiling in the carb.)

- 4/2013 to 8/2013 Tractor stalls/floods out after being placed in idle and leaks gas like above from the rubber tube.

- 9/2013 After leaf pickup I take carb to local shop to clean fix.

- 10/2013 Month later I take home and it not only leaks after shutdown but now the governor can't steady the carb and surges back and forth after it warms up. (I called shop... they only replaced the bowl gasket!)

- 12/2013 I take apart/clean the carb and replace the float and float needle, (whole carb is discontinued. Float seat can't be removed but looks ok after cleaning), but the leakage remains, won't idle but the governor doesn't surge as much.

thank you


#10

S

smitn

FYI Kawasaki FC540V single Cyl. on lx186.. had lots of odd running intermit problems, with gas leaking from overflow tube behind carb, sometimes a lot, other times seemed to work with out leaking.. ended up being bad float(plastic).. tried to repair by drilling hole draining drying, etc. then resealing, but didn't use the correct sealant?? bought new float $25+~ and working fine since., approx 1 year. If had to do again would have tried sealing with JB Weld, maybe would have saved a few $$ as i have repaired Plastic Radiator tanks, etc. and worked great.


#11

I

ILENGINE

smitn said:
FYI Kawasaki FC540V single Cyl. on lx186.. had lots of odd running intermit problems, with gas leaking from overflow tube behind carb, sometimes a lot, other times seemed to work with out leaking.. ended up being bad float(plastic).. tried to repair by drilling hole draining drying, etc. then resealing, but didn't use the correct sealant?? bought new float $25+~ and working fine since., approx 1 year. If had to do again would have tried sealing with JB Weld, maybe would have saved a few $$ as i have repaired Plastic Radiator tanks, etc. and worked great.
Click to expand...

I have used a hot glue gun in a pinch for plastic floats. Gas doesn't soften the hot glue. Repaired a float on a customers generator 3 years ago, during a week long power outage following an ice storm. Genny is still running without issue.


#12

F

fcctucke

8950LX said:
Hi all,

I've got an LX188 with the Kawasaki FD501V. I recently noticed after shutdown fuel coming from the bowl vent on the top of the carb. This explains the mystery fuel smell I've had for a few months now. I took the carb apart and it was surprisingly clean inside. The float needle however did show some slight wear on the sides and I suspected maybe it was sticking in the needle bore and not seating properly hence the overflow. So I ordered a carb kit from the dealer, replaced all the components in the kit including a new needle. Fired her back up, warmed her up thoroughly and low and behold it leaked(overflowed) again a few seconds after shutdown. I've checked the vent hole on the fuel cap to make sure it wasn't holding pressure or any sort of vacuum and that seems to be working fine. Is there anything I'm overlooking such as maybe fuel line routing(siphoning effect)? I'm very familiar with carbs of all sorts and I'm starting to think that possibly the seat is simply worn in this carb and maybe I'm due for a replacement carb. Any thoughts or suggestions are greatly appreciated. :cool:

Thanks,
Bill
Click to expand...

Hi Bill,

Have you checked that the fuel shut off solonoid is operating correctly? There is no way for the fuel to enter the carb if the shut-off solonoid is in the off position. When 12V supply to the shut-off wire is removed by the key the spring-loaded solonoid pushes a tapered point into the inlet. John Deere provided this extra function to prevent backfires.

,Fred


#13

PJ

PJ

8950LX said:
Hi all, I've got an LX188 with the Kawasaki FD501V. I recently noticed after shutdown fuel coming from the bowl vent on the top of the carb. This explains the mystery fuel smell I've had for a few months now. I took the carb apart and it was surprisingly clean inside. The float needle however did show some slight wear on the sides and I suspected maybe it was sticking in the needle bore and not seating properly hence the overflow. So I ordered a carb kit from the dealer, replaced all the components in the kit including a new needle. Fired her back up, warmed her up thoroughly and low and behold it leaked(overflowed) again a few seconds after shutdown. I've checked the vent hole on the fuel cap to make sure it wasn't holding pressure or any sort of vacuum and that seems to be working fine. Is there anything I'm overlooking such as maybe fuel line routing(siphoning effect)? I'm very familiar with carbs of all sorts and I'm starting to think that possibly the seat is simply worn in this carb and maybe I'm due for a replacement carb. Any thoughts or suggestions are greatly appreciated. :cool: Thanks, Bill
Click to expand...

Yes the seat could be warn or the float and needle adjustment could be be insufficient. Has the needle got a rubber tip?

PJ


#14

O

Ohsoblue92

I'm kind of new here but would a simple inline fuel cut off valve placed before the carb solve the problem?


#15

PJ

PJ

Ohsoblue92 said:
I'm kind of new here but would a simple inline fuel cut off valve placed before the carb solve the problem?
Click to expand...

Sorry I have not got info on this mowers carburetor lets see if some of our older hands has a answer.

Regards
PJ


#16

J

jakeamondo

found this article

PostPosted: Wed Apr 15, 2009 6:12 am Post subject: Re: LX188 Kawasaki FD 501V carb issues
I spoke to Steve at Mikuni America-the carb maker. He advises me that if the float needle were worn, fuel would come out of the overflow tube at the top.

He advises me to place a new float bowl O ring and remove the fuel injector cleaner gas in the tank and fill with fresh gas.

There is a pilot fuel jet in the top of the carb which he also advises cleaning.

However in my opinion the fuel solenoid valve would have to be stuck in open position. Test solenoid with 9 volt battery, positive to terminal, negative to ground. you should here it click.


#17

A

arch252

Sorry to resurrect on old thread. I have an FD590V on a JD345. I cleaned the carb and it is running amd idling great but gas is leaking out of the vent tube on top of the carb while it is running. It will start and stop overflowing while in high idle but pumps out the overflow heavily when reduced to low idle. Is that a needle valve seat / float issue or something else? Not leaking after engine is shutdown, only while running.


#18

B

bertsmobile1

fcctucke said:
Hi Bill,

Have you checked that the fuel shut off solonoid is operating correctly? There is no way for the fuel to enter the carb if the shut-off solonoid is in the off position. When 12V supply to the shut-off wire is removed by the key the spring-loaded solonoid pushes a tapered point into the inlet. John Deere provided this extra function to prevent backfires.

,Fred
Click to expand...

You are wrong with this one.
The shut off prevents fuel going through the main jet.
It does not stop fuel entering the carb. It is designed to stop fuel entering the engine in the few revolutions after you kill the engine and flowing unburned out the exhaust because the kill switch shuts off the spark.

What is happening here is the float valve is not holding back the fuel after shut down so the fuel bowl overfills and fuel flows out of the AIR VENT on top of the carb.
Nothing is flowing through the main jet.
I have come across this problem when gravity fed carbs have been used to replace fuel pump carbs because the float does not have enough closing force to to overcome the pressure from the fuel pump.


#19

B

bertsmobile1

Back to the original problem.
I rather think you have a small hole in the pump diaphragm this is allowing crankcase pressure to over pressureize the fuel line and lift the float needle and push fuel out the overflow.
The other possibility is the heat from the engine is heating the fuel in the bowl & either boiling it or just expanding it enough to overflow when then engine is off and there is no cooling air flow.
Last thought is bad fuel tank vent over pressureizing the fuel lines after shut down again lifting the needle. Remove the fuel cap when you finish mowing to check this .

Try putting an inline fuel tap between the pump and the carb.
A band aid solution but it should stop a pressure problem.
If it still overflows then it will be a heat problem.


#20

A

arch252

It will ovreflow fuel from the top vent tube immediately upon starting so that's not the problem. I replaced with fuel pump and no changes so rule that out. I had already checked the vent hole on the gas cap, that was one of the first things I did.

So, having ruled all that out, can this be a worn needle valve not seating? The fact that the overflow really comes out much more when it's idled down would seem to support this.


#21

B

bertsmobile1

Quick & dirty test is to pinch off the fuel line remover the float bowl, hold the float and see if it cuts off the fuel flow before the float touches the top of the carb body.
In most carbs the top of the float should be parallel to the bottom of the carb when it cuts off the fuel supply


#22

A

arch252

I sure wish they made those bowls out of some type of clear plastic. That would save me a lot of money and misery.


#23

U

union farm

arch252 said:
Sorry to resurrect on old thread. I have an FD590V on a JD345. I cleaned the carb and it is running amd idling great but gas is leaking out of the vent tube on top of the carb while it is running. It will start and stop overflowing while in high idle but pumps out the overflow heavily when reduced to low idle. Is that a needle valve seat / float issue or something else? Not leaking after engine is shutdown, only while running.
Click to expand...

Am new here and just wanted to post a possible answer to the overflow tube problem, Have a lx 172 with Kawasaki engine, fuel gushes out the overflow/vent tube while cranking or running. I removed and cleaned carb float and needle seat and reinstalled everything looked good and clean, no change!. However after reading a number of other sites with the same story and problem,wondered even if float looks good and doesn't leak could it be a bitt swollen above tolerance and rubbing on bowl causing no seating of needle. Ethanol could cause minor swelling of float? After inspecting bowl noticed a small casting bump in lower bowl [aluminum bowl] took a small grinder an polished out this casting bump and put back together. Can only surmise the float had swelled just enough to rub against this casting mark which wasn't much but enough to interfere with the float movement. No more leak and runs fine.


#24

B

bertsmobile1

union farm said:
Am new here and just wanted to post a possible answer to the overflow tube problem, Have a lx 172 with Kawasaki engine, fuel gushes out the overflow/vent tube while cranking or running. I removed and cleaned carb float and needle seat and reinstalled everything looked good and clean, no change!. However after reading a number of other sites with the same story and problem,wondered even if float looks good and doesn't leak could it be a bitt swollen above tolerance and rubbing on bowl causing no seating of needle. Ethanol could cause minor swelling of float? After inspecting bowl noticed a small casting bump in lower bowl [aluminum bowl] took a small grinder an polished out this casting bump and put back together. Can only surmise the float had swelled just enough to rub against this casting mark which wasn't much but enough to interfere with the float movement. No more leak and runs fine.
Click to expand...

:welcome: :thumbsup:


#25

A

Auzivision

This is a great thread!

I am new here as well and have been researching this topic after my John Deere LX188 caught fire.

I've traced the source of fuel to the carburetor vent line pouring fule directly onto the muffler.

Both the fuel pump and carb are new so I'm not sure which to attack first?

Either the pump is creating too much pressure or the carb float/needle/seat isn't stopping the flow properly.

I think I will star with the float using a makeshift gravity feed to replicate fuel pump. Does anyone have a good idea of how much elevation would generate the approximate fuel pressure of the pump?


#26

B

bertsmobile1

A foot or two will be fine.
Compressed air turned down low will also work a treat.
An impulse pump will run at around 7 psi & a mechanical pump should be around the same but some can get to 10 psi.

If you have a fuel line that is falling apart it can very quickly foul the float valve needle.
And a new carb is no guarantee a good carb.
There is a lot of defective parts being sold cheap on the web.


#27

H

Hitechluddite

Everybody is looking at the seats but has a float adjustment been made?

As far as finding a carb.

https://www.ebay.com/sch/i.html?_fr....XLX188+c.TRS0&_nkw=lx188+carburetor&_sacat=0

I'll admit ebay is somewhat of a crap shoot on these things, I've ordered 4 carbs for 4 different small engines and one needed mods and worked OK. One didn't work for crap and two were bolt on and perfect. For $20 it's something to consider...


#28

B

bertsmobile1

Hitechluddite said:
Everybody is looking at the seats but has a float adjustment been made?

As far as finding a carb.

https://www.ebay.com/sch/i.html?_fr....XLX188+c.TRS0&_nkw=lx188+carburetor&_sacat=0

I'll admit ebay is somewhat of a crap shoot on these things, I've ordered 4 carbs for 4 different small engines and one needed mods and worked OK. One didn't work for crap and two were bolt on and perfect. For $20 it's something to consider...
Click to expand...

Most carbs are available through the regular after market parts newtwork.
They are usually only 10% more than the ebay/amazon cheapies and come with a warranty.
It always amazes me why people would play the parts lottery on ebay & amazon.
hen again it amazes me why people donate their money to multi billionairs buying regular lottery tickets , or as my maths professor used to call them "Idiot tax for the mathematically challenged "
We just elected a government on the back of a $10/week tax reduction.
The average spend on all forms of gambling down here is $ 215 /week per tax payer ( casinos excluded )


#29

D

deckeda

Hitechluddite said:
Everybody is looking at the seats but has a float adjustment been made? ...
Click to expand...

Hey! Somebody used to work with old cars. But, that won't be an option on these floats that don't use a bendable brass arch at the fulcrum. That method thankfully went away a long time ago (uh, I hope.)

Summary:
For gas that flows out "all the time" look at the suggestions related to float swelling (binding against the bowl), float needle worn, and needle seat worn/dirty

For gas that flows after shutoff look at the suggestions related to excess fuel pressure caused by a worn or damaged pump ... especially before you tear into any discontinued Mikuni carb. I have the emotional scars to prove it.


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