fuel gauge head scratcher

[LouNY]

Had an interesting issue with my 8050 the last couple of weeks.
Fuel gauge quit working properly, wouldn't read above a 1/4 of a tank.
Raking hay for a few days with her when the gauge guit, got the low fuel light so brought down a couple of cans of fuel.
Only poured about 6 gallons in when it was over full, spilled out the filler neck. Low fuel light cleared back to work.
Filled up at the farm pumps a few times (no meter) while doing some brush hogging and cleanup, different operators,
low fuel light a couple of times run over and fill it. Brought it home to do some driveway work knew she was full so ignored the
gauge and then the low fuel light all of a sudden started losing power got her turned sideways on the driveway the engine straightened ran good so started to work again and it happened again got her turned and running good and backed up the hill to the fuel tank (gravity fill no meter) filled her up didn't take long and back to work.
Started looking for the fuel sender, lifted the floor mat in the cab a nice little round hole to access the fuel sender, OK of course I can't reach the connector to disconnect it, called my dealer to check price and availability of the sender (almost $140) recommended dropping the tank (s) to replace. The 8050 has a 2 piece fuel tank a front section and then a main tank. Decided to pull the sender who knows maybe just a loose wiper on the resistor. Nope no simple sender here got a fancy sensor assembly, rod tube over 1/2" diameter with a float around it ( going to assume reed switches with a magnetic pull in) raised and lowered float gauge worked fine, hum called told dealer not to order sensor. Measured the fuel in tank only 5" should have been 3/4 s full, reading 1/4 full, filled a can and poured in 5 gallons reading about 1/2 whats going on now. Buttened the sensor back up in tank and fill jug again started pouring fuel in 4 gallons latter over filled at the filler neck????? checked gauge just over 1/2 went to the rear of the tractor and pulled a vent line of the tank fuel dropped in filler neck gauge reading almost 3/4 full.

The danged mud dabber wasps had plugged both of the fuel tank vents, on one they had even gotten down 6" in the hose from the tank to the vent gooseneck, the other just the gooseneck was plugged when they had finally sealed both vents the main tank wasn't being filled just a splash about a quarter in the main tank and filling the front section we were operating with maybe 8 gallons capacity on a 26 gallon tank but not having meters on the fuel dispensing tanks never realized we weren't filling the tank.

 

[Branson Bob]

Had an interesting issue with my 8050 the last couple of weeks.
Fuel gauge quit working properly, wouldn't read above a 1/4 of a tank.
Raking hay for a few days with her when the gauge guit, got the low fuel light so brought down a couple of cans of fuel.
Only poured about 6 gallons in when it was over full, spilled out the filler neck. Low fuel light cleared back to work.
Filled up at the farm pumps a few times (no meter) while doing some brush hogging and cleanup, different operators,
low fuel light a couple of times run over and fill it. Brought it home to do some driveway work knew she was full so ignored the
gauge and then the low fuel light all of a sudden started losing power got her turned sideways on the driveway the engine straightened ran good so started to work again and it happened again got her turned and running good and backed up the hill to the fuel tank (gravity fill no meter) filled her up didn't take long and back to work.
Started looking for the fuel sender, lifted the floor mat in the cab a nice little round hole to access the fuel sender, OK of course I can't reach the connector to disconnect it, called my dealer to check price and availability of the sender (almost $140) recommended dropping the tank (s) to replace. The 8050 has a 2 piece fuel tank a front section and then a main tank. Decided to pull the sender who knows maybe just a loose wiper on the resistor. Nope no simple sender here got a fancy sensor assembly, rod tube over 1/2" diameter with a float around it ( going to assume reed switches with a magnetic pull in) raised and lowered float gauge worked fine, hum called told dealer not to order sensor. Measured the fuel in tank only 5" should have been 3/4 s full, reading 1/4 full, filled a can and poured in 5 gallons reading about 1/2 whats going on now. Buttened the sensor back up in tank and fill jug again started pouring fuel in 4 gallons latter over filled at the filler neck????? checked gauge just over 1/2 went to the rear of the tractor and pulled a vent line of the tank fuel dropped in filler neck gauge reading almost 3/4 full.

The danged mud dabber wasps had plugged both of the fuel tank vents, on one they had even gotten down 6" in the hose from the tank to the vent gooseneck, the other just the gooseneck was plugged when they had finally sealed both vents the main tank wasn't being filled just a splash about a quarter in the main tank and filling the front section we were operating with maybe 8 gallons capacity on a 26 gallon tank but not having meters on the fuel dispensing tanks never realized we weren't filling the tank.

So Lou... your long national nightmare is over?

 

[LouNY]

Well the fuel tank issue is taken care of for now anyways.

 

[K5lwq]

That is crazy! Hate how things like that will drive you nuts trying to get it fixed. Dang dirt daubers!

 

[oosik]

Several years ago I had problems with mud daubers. They would lay eggs & a couple dead spiders in the key slot on my riding mower. Then cap it off with some yellow sticky snot. I fought it all summer. Then - what the heck - I just left the key permanently installed in the slot.

I use a short chunk of sticky-backed foam tape on my new mower. Over the years I've lubed the heck out of the key slot on the tractor. They don't bother it.

 

[Cougsfan]

I am glad you posted this Lou. Until you posted it I didn't realize that my 4720ch had even had two inter-tied tanks. If I'd have looked the tractor more closely I would have realized it, but it just never occurred to me to look until I saw your post. My problem is that my tractor acts like it has about a 6 gallon tank. My tractor will run out of fuel if there is any kind of side hill, and will only take 5 gallons to fill it. It is supposedly a 9.3 gallon capacity. My fuel gauge is so extremely erratic that I ignore it. I replaced the sending unit some time ago (under warranty) and it didn't help.
I am suspecting I might have a plugged vent line in the right side tank after reading what you have gone through, but have no idea how to access it.

I looked at the parts diagram. It is really screwed up and incomplete in labeling parts. The service manual also doesn't explain very well about things around the fuel tank either.

Guess I will just have to crawl under the tractor (one of my least favorite things to do) and see what I can find. I know the vent line exits right above the 3 point top link. How did you unplug your line, Lou? Can I just blow it out with air? Unfortunately I just filled my tank so I probably should run it down a ways first if I have to tear anything apart

 

[LouNY]

I could access the hoses where they came off of the fuel tank and my "vents" which are simply 180 degree bends of tubing just under the rear window.
I pulled the hoses and couldn't blow air through them with my compressor and blow gun, after flexing the hose and finding the hard spots and really flexing them,
I could get the air to blow through and then I sprayed in carb cleaner and blew that thru then ran a piece of all thread (#10) through the 1/4" hose,
it took quite a bit of spraying and poking with a tie wrap to get through the vent tubes.
I'm going to add cheap fuel filters to the vents to try and keep the mud dabbers out.

 

[LouNY]

I am glad you posted this Lou. Until you posted it I didn't realize that my 4720ch had even had two inter-tied tanks. If I'd have looked the tractor more closely I would have realized it, but it just never occurred to me to look until I saw your post. My problem is that my tractor acts like it has about a 6 gallon tank. My tractor will run out of fuel if there is any kind of side hill, and will only take 5 gallons to fill it. It is supposedly a 9.3 gallon capacity. My fuel gauge is so extremely erratic that I ignore it. I replaced the sending unit some time ago (under warranty) and it didn't help.
I am suspecting I might have a plugged vent line in the right side tank after reading what you have gone through, but have no idea how to access it.

I looked at the parts diagram. It is really screwed up and incomplete in labeling parts. The service manual also doesn't explain very well about things around the fuel tank either.

Guess I will just have to crawl under the tractor (one of my least favorite things to do) and see what I can find. I know the vent line exits right above the 3 point top link. How did you unplug your line, Lou? Can I just blow it out with air? Unfortunately I just filled my tank so I probably should run it down a ways first if I have to tear anything apart

I just looked at the parts breakdown for the 4720 it looks like your vent lines are coming off of the upper area on the inside of the fuel tanks,
they could be difficult to reach. I got lucky in that mine were easy to reach.
If you are lucky and the restriction is just at the end under the vent, removing the hose below it may help, on mine the mud dabbers had gotten 6" down in the hose so I had to remove the hoses to blow from the tank end towards the vent end to keep crap out of the tank.
Is your fill cap on the right tank or the left in the picture it looks like the right side, if so I would suspect either the other tank or after the tee.
As I could fill the portion with the cap as it vented while filling it.

 

[Cougsfan]

Sure enough, The vent line was plugged solid. I looked in the down the end and it looked like there was an orange plug in it. I cut off the last two inches, that orange plug ended up being a paper like material packed in very tight. I wouldn't know a mud dabber if I saw one, but something sure plugged it up. The material went further up the line. I cut off as much as I could (about a foot) and it was still full of this stuff!

I looked at pulling the entire vent line, but that would be a very difficult task. No way I can get my hand up to disconnect them at the tanks and the tee is totally inaccessible. So I pinched off each vent line out of each side of the tank, one at a time, and blew air through them. They cleared ( I boiled a bit of fuel out of the fill spout in doing so).

Afterwards I was able to put about 4 gallons in the tank (I filled the tank yesterday, ran about a gallon out today by using the tractor, and boiled maybe a pint or quart at the most out when blowing the lines). So I obviously didn't fill both tanks yesterday.

Time will tell, but I am pretty sure that things will work better (I might be able to go more than 5 hours on a tank of gas and my fuel gauge might actually work)

Thanks again, Lou, for pointing bringing this subject up.

 

[Texasmark]

I am glad you posted this Lou. Until you posted it I didn't realize that my 4720ch had even had two inter-tied tanks. If I'd have looked the tractor more closely I would have realized it, but it just never occurred to me to look until I saw your post. My problem is that my tractor acts like it has about a 6 gallon tank. My tractor will run out of fuel if there is any kind of side hill, and will only take 5 gallons to fill it. It is supposedly a 9.3 gallon capacity. My fuel gauge is so extremely erratic that I ignore it. I replaced the sending unit some time ago (under warranty) and it didn't help.
I am suspecting I might have a plugged vent line in the right side tank after reading what you have gone through, but have no idea how to access it.

I looked at the parts diagram. It is really screwed up and incomplete in labeling parts. The service manual also doesn't explain very well about things around the fuel tank either.

Guess I will just have to crawl under the tractor (one of my least favorite things to do) and see what I can find. I know the vent line exits right above the 3 point top link. How did you unplug your line, Lou? Can I just blow it out with air? Unfortunately I just filled my tank so I probably should run it down a ways first if I have to tear anything apart

Pull up your rubber floor mat. You may be pleasantly surprised at what you'll find......access plates.