Disappearing fuel

[Ivan]

So, a week or so ago I rode the naked venture into town and fueled it up. I hadn't had it on the road before and needed to make sure it was capable of motorating under its own powerization. It works ok, now its time to start painting,,,

 

Anyhoot. In the mean time, the whole house smells of gasoline, and I go out to check on it, and it has lost all the fuel. The tank is bone dry. The concrete isn't wet and it didn't leak out while running, so I am pretty sure it isn't the carbs. Are there any typical leak points on these scoots, or should I figure on removing the tank to repair rust?

[GeorgeS]

Thats a new one !!! ---

 

I would say, put it outside, add maby 1/2 gallon, put newpaper under the bike, and post your guard dog to watch it. !!

 

 

OK, first place I would check, is the Fuel Petcock. It has a rubber gasket between the valve, and bottom of tank. Check the two small bolts that hold the petcock in place.

 

now Inspect the Fuel Line that runs from the petcock, across under the tank to the Fuel filter. That Line Might be leaking.

 

There is a Clamp, welded to bottom of tank, that holds this fuel line in place.

The cross over line, that is.

 

then check the fuel line from the Fuel filter, going to the Fuel Pump.

 

then Check the Fuel Pump itself. It is a Two Part Unit, Gasket between the two parts. which might be leaking.

 

Only other thing would be a leak in the Tank Itself, However this would be an obvoious leak !!! And if tank is empty, bone dry as you say, would have to be near the lowest Point of the Tank.

 

????

[ToRide1]

Check to see if the oil is contaminated with gasoline, one of your carburetors could be varnished up at the needle seat and its leaking very slowly into the cylinder and down past the rings. I have seen this happen a few times over the years.

[bobcat]

I agree with ToRide.....If that much fuel isn't hitting the ground then logic would say its going in your crankcase...(However, logic doesn't always work..)

I had a similiar problem with my BMW except I didn't loose a lot of fuel..The garage smelled like gas and my mileage went down...It wound up being a leaking fuel line...this was during the summer so I'm guessing the gas probably evaporated before it puddled...

[MiCarl]

Check to see if the oil is contaminated with gasoline, one of your carburetors could be varnished up at the needle seat and its leaking very slowly into the cylinder and down past the rings. I have seen this happen a few times over the years.

 

1st gen isn't gravity feed. Carburetors are higher than half the tank. If it's really bone dry carburetor aren't the issue.

[Freebird]

As for common issues, it is NOT unusual for the tanks on the early models to rust out and leak. Several here have had to change them out.

[Ivan]

As for common issues, it is NOT unusual for the tanks on the early models to rust out and leak. Several here have had to change them out.

 

I am wondering about this. As soon as I get some time I will check it out. If I do have to change it out, I think I am gonna get "Joe Dirt" on the old one and shoot fireworks at it.

[ToRide1]

I am wondering about this. As soon as I get some time I will check it out. If I do have to change it out, I think I am gonna get "Joe Dirt" on the old one and shoot fireworks at it.

 

I was reading some where on the internet, there are a few people that can save an old car or truck gas tank and what the do to it is! Sand blast inside and out to get rid of rust and to do this part they have cut a hole but on a motorcycle tank they can cut into the inside part that raps around the frame so you will never see it, and what oxidation is left they use a chem. on it then use some thick epoxy to coat the inside and the hole they had to cut gets a patch welded over it. Just a little info for any that want to know that.

[Squidley]

Just for giggles check the oil level in the crank case, if for nothing more than being over cautious. The paper underneath is a great idea too, run it and see where it's coming from.

[painterman67]

I was reading some where on the internet, there are a few people that can save an old car or truck gas tank and what the do to it is! Sand blast inside and out to get rid of rust and to do this part they have cut a hole but on a motorcycle tank they can cut into the inside part that raps around the frame so you will never see it, and what oxidation is left they use a chem. on it then use some thick epoxy to coat the inside and the hole they had to cut gets a patch welded over it. Just a little info for any that want to know that.

 

 

Had this done to a previous atv I had and it held for years.

 

good luck

david

[Dragonslayer]

As for common issues, it is NOT unusual for the tanks on the early models to rust out and leak. Several here have had to change them out.

And gas on the ground will evap quickly leaving a gas smell in the air it is possible a slow leak can evap at near the same rate not leaving a puddle. Watch out for open flames.

[mraf]

Check the engine crankcase as has been said. Especially if you don not see any gas under it. I am now waiting for a carb rebuild kit for my Suzuki 250 4 wheeler. I filled it up when gas was $1.65 only to find it empty last Tuesday. Pulled the drain plug and aha there is were all the gas went. Now mind you this 4 wheeler has a fuel pump that runs off of the engines vacuam to run it and it sets higher than the engine. You would think that this would stop the gas but it doesen't. Once the float needle wears it lets the gas leak past instead of shutting it off like it should.

[bobcat]

1st gen isn't gravity feed. Carburetors are higher than half the tank. If it's really bone dry carburetor aren't the issue.

 

Excellent point.....I was comparing My BMW, which is gravity fed, to the Yamaha which is not gravity fed...Duh