losing gas

[old hippy]

Wife and I went for a ride today. Stopped a half hour from home and filled the tank. Went out a little later to put the bike away and no gas. I have checked the lines on the filter and fuel pump and they appear fine. Then I checked the main feed line coming from the tank to the fuel pump and it seems fine. The line coming off of the reserve tank appears fine. The overflow tube is dry at the end. I see no gas on the ground and I do not smell any gas and the wife didn't smell any while riding. Everything I have checked seems fine. I haven't removed the tank yet. What haven't I checked or where do I go from here?

[eagleeye]

How did you determine that you had no gas?

 

The first thing that I would do is check my oil level.

 

Steve

[old hippy]

The fuel light was on and the fuel gauge is showing no bars. I used a dowel and there is only about an inch of fuel in the tank. I just checked the oil and guess where the gas is. What should I check first?

[jneed53]

Does your tank lock? Someone may have siphoned it. Never mind -- now I see that it went southward.

[GeorgeS]

You can't see the bottom of the tank thru the filler cap!

 

There is no way 5 gallons of gas can escape without seeing it!!

 

Put bike on center stand, pour in a gallon, if the tank is leaking you will see it somplace.

 

I have heard of one guy that the bottom of his tank rusted out. But only one.

 

Also, turn key to " ON" position so the fuel pump runs, if any hose is leaking, then the pump will force it thru the Leak, and you should see it.

[old hippy]

My gas is now in my oil. I don't know how or where. I need to know where to start. Wrenching isn't something I'm real strong in. Any help out there?

[Yammer Dan]

DON"T START. May not do anything but still not good for it. Oil is going to have to come out. You must have a carb acting up and dumping gas down the throat. Going to have to pull air box to see this probally. Someone else may get in here with saftey things. Keep a Fire extinguser handy when messing with gas. Turn switch on after you get air box out of the way and see which carb is pumping fuel thru and out the overflow. Shut off as soon as you see this and get something to rap on this carb with . I use a long 3/8 extension. Tap it sharply several times around the bowl area and turn switch on to see if it stopped. If you are lucky it will be cured. Let us know and don't blow it up!! Need strong dose of Sea-Foam if this works. I would use 1/2 can in gallon of gas. Run it til it gets into carbs good and leave sit for while overnight or day or two.

[nance56]

BUMP

[Guest Boss Hogg]

If the float or needle and seat is by-passing it will just flow out the over-flow tube and drain onto the rear shock

[endo]

Even if the overflow tube were blocked it would be a trick to have it all dump into the crankcase. It would be smelling real gassy at any stop, and running poorly, besides. That cylinder certainly wouldn't fire. it would pour out all over the V between the cylinders, splash in the airbox, too. The gauges are known to act up if a spot on the fuel-level float metering potentiometer is worn. It would drop to zippo and bounce back up in another quart of usage. You can't dipstick the tank too easily...

[eagleeye]

If you have'nt done anything yet, start by draining the oil. Now, keep in mind that you have a gal of oil and maybe 5 gal of gas in there. You will need a BIG drain tank.

If you aren't the kind of guy to take the carbs apart, then you need to take it to a mech. Somehow a float stuck open or like was mentioned, a needle stuck, or something like that.

Keep in mind that all of that gas just wiped away all of your lubrication inside of your engine, so when you fire it up, keep the RPM's low for a while.

I'm not a mechanic, but I do tinker,

 

Steve

[Guest Boss Hogg]

pull the seat and check the connections and the wires they do have a chaffing problem in that area

[Gearhead]

"

If the float or needle and seat is by-passing it will just flow out the over-flow tube and drain onto the rear shock"

 

 

 

I don't think so. The "overflow" is actually a vent and is higher than the jet, so it will flow out into the intake port first. I think the EPA declared overflows onto the ground uncouth.

 

Jeremy

[Tupperj]

In the gravity fed world of XS and XJ bikes I from, this is called GasOil. Happens when the float needles stick open and the vacuum operated petcocks fail. Lots of gas flows out of the carb, and if the intake port is open, into the cylinder, past the rings and into the crankcase.

 

Problem with that here, is the fuel pump. Is there any chance the bike was left on, so that the fuel pump would continue to run after shutdown? That would be the only way I can see for the tank to empty. I'd suggest checking the fuel pump to make sure it is powering down when it should.

 

My .02, worth pretty much what you paid for it.

 

Paul

[BOO]

Sounds like you may have a couple of problems.

Keeping in mind I now have an RSV.

Keep in mind I am a carpenter.

Gas will run out the overflow tube if you have a float sticking. BUT mine only did that with the key on making the pump pump.

We use to shut off the petcocks to stop the gas from doing exactly what has happen to your bike BUT that bike has a vacuum shut off petcock.

My opinion there is one thing for sure, you have a float stuck.

Maybe for some odd reason the fuel pump is not shutting off with the key.

Good Luck,

Jerry

[rhncue]

On these bikes, the pump will only run when the motor is running. It will only pump for a couple of seconds when the ignition is turned on and then quits. If you want to check for leaks or carbs over flowing you have to keep turning the ignition on and off. I can see no way that the carbs could possibly leak a tank of gas into the crankcase after the bike has been turned off as once the carb is empty it cannot be refilled unless the motor is running. If the gas ran out after stopping then there has to be a leak either in the tank it self or the line running to the fuel tank to the pump.

 

Dick

[GeorgeS]

Rhncue has a good point. The Line from the Pump that goes to the 4 carbs, might have a Split in it.

 

The pump runs till the pressure builds up ( I think 3 lb ) then shuts off. If there is a leak up line from the pump, it will just keep running as the pressure will never build up.

 

Pull out the Air Box, and Check all the lines from the pump, goiing to top of the 4 carbs. You might find a split rubber hose somplace,

 

Also, turn Off the Petcock, and Remove the line from the Petcock to the fuel filter, it might be leaking.

 

Also, pull out the Fuel Filter, if is plastic, it could very easily have a crack in it.

 

Also check the Hose from filter to the Pump. It could be Split.

 

To sum this up. Pull out All the Hoses!! and examin them for leaks, before you tear into the Carbs.

 

There are several rubber hose sections on top of the Carbs that could be leaking.

 

One more thought: Remove the Right Side Passenger foot rest assembly, now useing a bright light, examine the Fuel Line going from the Petcock across, and under the bottom of the tank to the fuel filter on the left side of bike. The Hose has to Fit in a Clip which is welded to the bottom of the tank. Why?? If the Hose falls out of this clip, which holds it forward of the rear tire, it can move back and rub against the rotating tire, and that will wear a hole in it. However if this was the case you should see gas running out. But Just a thought.

[BOO]

I agree with everything you said BUT his crankcase is full of gas and the only way I can think of for it to get in there is through the Carb.

Again, if the float is stuck open it will let the gas pump right through BUT something has to be wrong in the electrical circuit to let the pump run with the key off. OR the valve is not shutting the gas off and it is running through.

I'm not a 100 percent sure of what I am saying but that's why I said it takes two problems for this to happen.

Wish I was closer so I could help,

Jerry

 

 

 

Rhncue has a good point. The Line from the Pump that goes to the 4 carbs, might have a Split in it.

 

The pump runs till the pressure builds up ( I think 3 lb ) then shuts off. If there is a leak up line from the pump, it will just keep running as the pressure will never build up.

 

Pull out the Air Box, and Check all the lines from the pump, goiing to top of the 4 carbs. You might find a split rubber hose somplace,

 

Also, turn Off the Petcock, and Remove the line from the Petcock to the fuel filter, it might be leaking.

 

Also, pull out the Fuel Filter, if is plastic, it could very easily have a crack in it.

 

Also check the Hose from filter to the Pump. It could be Split.

 

To sum this up. Pull out All the Hoses!! and examin them for leaks, before you tear into the Carbs.

 

There are several rubber hose sections on top of the Carbs that could be leaking.

 

One more thought: Remove the Right Side Passenger foot rest assembly, now useing a bright light, examine the Fuel Line going from the Petcock across, and under the bottom of the tank to the fuel filter on the left side of bike. The Hose has to Fit in a Clip which is welded to the bottom of the tank. Why?? If the Hose falls out of this clip, which holds it forward of the rear tire, it can move back and rub against the rotating tire, and that will wear a hole in it. However if this was the case you should see gas running out. But Just a thought.

[Gearhead]

"Again, if the float is stuck open it will let the gas pump right through BUT something has to be wrong in the electrical circuit to let the pump run with the key off. OR the valve is not shutting the gas off and it is running through."

 

 

 

Other than the protrusion up by the filler cap, the tank is below the level of the carbs methinks, so that even if the pump was letting fuel by when not running, it wouldn't run uphill into the carbs.

 

Jeremy

[BOO]

Yeah, I thought about that. I know the tank is pretty low in those bikes but something has gone wrong for the gas to get in the crankcase.

I just don't know and I have never heard of this problem with these bikes before.

It will be interesting to find out what the problem is when he gets it fixed, that's for sure.

Jerry

 

 

 

 

Other than the protrusion up by the filler cap, the tank is below the level of the carbs methinks, so that even if the pump was letting fuel by when not running, it wouldn't run uphill into the carbs.

 

Jeremy

[Guest Ken8143]

I am curious - how many gallons of gas will the crankcase hold? Sounds like a lot is going in there! I wonder if there are several issues going on at the same time.

[Yammer Dan]

It had to go thru carbs to get in crankcase. Right? Could a float have stuck while it was running flooded that cylinder and just kept pumping fuel thru there while running? Sounded more like it ran thru there while sitting. What would it take to do this? Fuel pump has to keep running.

Check carbs first I would think. Like Denden wish I was close on this one.

[GeorgeS]

There is a pull apart plug about 6 inches from the Pump. L/B ( blue-black wire ) and a black wire going to ground.

 

Check here for voltage on the L/B wire with Ignition Switch OFF. There should not be any. ( If there is 12V here with the SW Off, then there has to be some crossed wires someplace. Also the Engine Stop Switch should remove voltage from the Pump.

 

The Pump Runs until the carbs are full, and the float valves close. the pump sences the pressure increase, then An INternal Switch INSIDE Of the Fuel Pump Opens, and the Pump stops running. When the fuel level drops in the carbs the switch in the pump closes, and pump Runs.

 

I am thinking that your problem Is the FUEL PUMP ITSELF!!. The Internal Switch, might be bad. HOWEVER, this could Only happen if the Ignition Switch was left in the ON POsition!!! OR, the L/B wire to the pump, is Cross shorted to another wire that is Hot with 12 volts, with the SW OFF.

 

Are you sure you did not leave the Switch ON ????????

[old hippy]

I'm glad to report that the fuel problem is no more. I dumped the old oil and put in fresh so we could start the bike to check the carbs. Started her up with the airbox off, being very carefull not to have my head over the carbs when she started. All four carbs had a good even flow and when I shut her down there was no fuel still flowing. Turned off the fuel and run her dry to check to see that the fuel pump was shutting off after it built pressure back on the line, and it did stop after about five seconds. Nance and think that sometime after we filled her up, one of the floats got stuck open with some dirt. We think it happened right before we turned her off, because none of the plugs fouled out. We had been having problems with the intercom and we had been turning the key on and off several times while we were checking it. If the float was stuck and the pump coming on every time we turned the key, were guessing thats how the fuel got into the crankcase. The main thing is that she's not hurt and she's running fine. I'm going to throw a can of SeaFoam in her tommorow, and keep a close eye on her. We would both like to thank everybody who put up posts to help us get her going. You guys were a big help. Thanks.

[BOO]

Glad to hear everything is okay. Sometimes we make to much out of a simple problem but when you ask for help on this forum you are definitely going to get a lot of opinions.

Good luck and like you said, keep an eye on it.

Maybe see you for the ride in at the Quad Cities......

Jerry