Interesting dissapearing gas act

XC Elko

New member
Went for a 5 mile ride with the kids, stopped at the gas station on the way back to top off the sleds. Got home parked the sleds and a day or two later I notice a yellowish snow patch under the 94 XLT and see a small drip coming from the bottom. My first thought is must of had a cooling line wear through or something along those lines. Pulled it into the garage a day later, opened up the hood and the coolant resevour is still half full. Hmmmm, open up the gas tank at it is almost completely empty! Looked at all the gas lines, they look good, no cracks or leaks that I can see. Anyway took off the seat to replace the seat cover (in meantime make sure there are no cracks in the tank, there wasnt it held gas fine after) put it back on, dump 2 gallons in and start it up. No leaks anywhere.

So my thinking is that maybe a float valve stuck open and it siphoned the tank over a day or so. Would that make sense? all the plugs are still in the drain lines coming off the bottom of the float bowls with no evidence of leakage around those. Does this make sense? I am a bit baffled as it would of had to siphon it out and the floats are the only area that are that low on the tank because it was almost completely empty. ticked I lost $30 worth of gas but probably cheaper than having to fix a cooling leak...Anyone want to take a Matlock stab at this scenario?
 
Went for a 5 mile ride with the kids, stopped at the gas station on the way back to top off the sleds. Got home parked the sleds and a day or two later I notice a yellowish snow patch under the 94 XLT and see a small drip coming from the bottom. My first thought is must of had a cooling line wear through or something along those lines. Pulled it into the garage a day later, opened up the hood and the coolant resevour is still half full. Hmmmm, open up the gas tank at it is almost completely empty! Looked at all the gas lines, they look good, no cracks or leaks that I can see. Anyway took off the seat to replace the seat cover (in meantime make sure there are no cracks in the tank, there wasnt it held gas fine after) put it back on, dump 2 gallons in and start it up. No leaks anywhere.

So my thinking is that maybe a float valve stuck open and it siphoned the tank over a day or so. Would that make sense? all the plugs are still in the drain lines coming off the bottom of the float bowls with no evidence of leakage around those. Does this make sense? I am a bit baffled as it would of had to siphon it out and the floats are the only area that are that low on the tank because it was almost completely empty. ticked I lost $30 worth of gas but probably cheaper than having to fix a cooling leak...Anyone want to take a Matlock stab at this scenario?

Leaking Fuel pump

Some fuel might be leaking into the crank case as well
 

XC Elko

New member
Leaking Fuel pump

Some fuel might be leaking into the crank case as well

are you thinking maybe a torn membrane in the fuel pump allowing it to bypass it as it sits there siphoning it out? I will have to check that out. There are definetly no leaks coming from the housing of the fuel pump. I would think this would show up in the performance of the machine but maybe not...
 
are you thinking maybe a torn membrane in the fuel pump allowing it to bypass it as it sits there siphoning it out? I will have to check that out. There are definetly no leaks coming from the housing of the fuel pump. I would think this would show up in the performance of the machine but maybe not...

If it isn't the fuel pump, you're neighbor's stealing your gas when you're not looking....................

Pull the pulse line off the engine (the rubber line connecting the case and the fuel pump) it should be dry.

and/ or

After the sled's been sitting for a while with fuel in the tank and the gas valve on, remove the drain plugs at the front of your engine and see if raw fuel comes out.(you may have to have your bud raise the rear of the sled to get the fuel to come out)

Those sleds typically have a MIKUNI fuel pump. Just pick up a rebuilding kit consisting of a new diaphragm and you're good to go.

Once you get that sorted out, add a 1/2 quart or so of POLARIS oil to a full tank of gas to replenish oil to the crank & rod bearings as the fuel splashing around in the crank case washed it all away.
 
Last edited:

flextx500

New member
Check the water trap lines coming off the bottom of the fuel bowls. I just had the same exact thing with a 97 XLT a few weeks ago. I filled the tank and a few days later the tank was empty and the trailer was covered with gas. The water traps, which are just of rubber fuel line on the bottom of the carbs had completely deteriorated. Had to take the airbox off to see it.
 

motor_slut

New member
Needle and seat
Stuck choke
Loose bowl
cracked/worn through fuel line

You can just turn the gas off if you are cheap.
 
Top