Gas leak under tank

[harpo]

My bike has been on blocks the past two weeks while the forks are off being rebuild.I started smelling gas and found several drops of gas on the ground on the right side of the bike. I lifted the tank and found where gas has leaked on the insolation blanket on top of the motor. I think it is coming from the gas line at the fitting but at this point im not sure. I wonder if the fitting itself or if the gasket where it bolts to the tank be the source. Has anyone had the gas fitting or any other point just start leaking?

 

[garyahouse]

Gas under the bike is normal when the bike's outside in the sun. The evaporation/drainage tube us doing it's job. Gas elsewhere, not so normal...

Gary

darksider #44

 

[Intech]

I think I read somewhere about that fitting cracking. The leak is at the fitting on the tank not the quick connect?

 

[wfooshee]

Gary's point is a good one. Make sure it's leaking and not just venting. Gas can evaporate when the tank is heated by sunlight, and it vents through a check valve in the cap assembly. If enough gets out it drains from a tube at the bottom of the bike.

You'd see more of this with a full tank, I think.

 

[Intech]

If he has leakage under the tank then it could only be the drain if it wasn't properly routed. If it is wet under the tank there must be something under there leaking. I know mine has "slipped" out of my grip a couple of times and had me concerned that I might crack that fitting.

 

[harpo]

I'm going to try to put the tank back on and move the clamp on the gas line up closer to the end. Beings that it just started leaking out of the blue the gas line may have just lost its seal and moving the hose clamp might make it seal off. It is in the garage and it isn't a vent related problem. I could see drops of gas hanging on the bottom of the of the fuel pump and gas line so eliminating the line may fix it.

 

[Donal]

I'm going to try to put the tank back on and move the clamp on the gas line up closer to the end. Beings that it just started leaking out of the blue the gas line may have just lost its seal and moving the hose clamp might make it seal off. It is in the garage and it isn't a vent related problem. I could see drops of gas hanging on the bottom of the of the fuel pump and gas line so eliminating the line may fix it.

I would disconnect the line completely, make sure everything is clean and looks to be in good condition, then apply a smear of silicone grease to the metal 'spigot' and re-connect.

 

[Intech]

I'm going to try to put the tank back on and move the clamp on the gas line up closer to the end. Beings that it just started leaking out of the blue the gas line may have just lost its seal and moving the hose clamp might make it seal off. It is in the garage and it isn't a vent related problem. I could see drops of gas hanging on the bottom of the of the fuel pump and gas line so eliminating the line may fix it.

I would disconnect the line completely, make sure everything is clean and looks to be in good condition, then apply a smear of silicone grease to the metal 'spigot' and re-connect.

The above is good advice as it will also allow you to closely inspect the tubing and gas tank connector.

 

[harpo]

Set the tank on a table and plugged the gas line and the other line port and gas still dripped. I pulled the fuel pump out and looked it over.There is no sign of a crack, so now I am thinking the rubber gasket between the pump and the tank is letting gas seep by.

Has anyone had a fuel tank gasket leak even though the pump has not been messed with?

 

[Canadian FJR]

Did you try and snug up the bolts for the base of the fuel pump?

Canadian FJR

 

[TownsendsFJR1300]

Yamaha recommends replacing this seal everytime the pump is removed (I know you didn't remove the pump).

I strongly suspect the rubber seal just flattened out with age and is leaking. Its easy to change out, just have to empty the tank. The torque of those bolts are very little, around 3 ft lbs as I recall.

MY mid gear, o-ring seal did the same thing from my 04.

https://www.partzilla.com/parts/search/Yamaha/Motorcycle/2003/FJR1300+-+FJR1300R/FUEL+TANK/parts.html

 

[Canadian FJR]

"Yamaha recommends replacing this seal everytime the pump is removed "

Thanks for that bit of info. I've removed my pump twice and just re-used the old seal. I will keep an eye on this.

Canadian FJR

 

[harpo]

All the screws were tight when I took the pump out but after looking the gasket over and putting it back on the pump I thought the gasket looked thin. I have ordered a new one.

 

[TownsendsFJR1300]

"Yamaha recommends replacing this seal everytime the pump is removed " Thanks for that bit of info. I've removed my pump twice and just re-used the old seal. I will keep an eye on this. Canadian FJR

On my 07 FZ6 (similar set up) I've re-used the seal twice, no issues (of course the seal is at least 4 years newer and more pliable).

The third time, (a tank replacement), I just replaced it, wasn't worth screwing around with. Its cheap enough insurance..