overflow petrol pipe

[andy194bikes]

hi guys, thxs for all the help from my last posts.got a new promblem now. u know the two pipes that come off the tank from underneath(as u sit on the bike)the one on the left is a breather and the other one is the overflow from the tank i think(none of these pipes connect anywhere to the carbs which is correct).wel it keeps dripping fuel ,very slowly but the tank only has half a tank and for the life of me i cant figure out while its doing it.any help suggestions appreciated.thxs.the bike is a 1993 fp model uk version.

[The CyberPoet]

You have two drains coming off the tank.

One of them connects to a tube that runs up to the top of the filler neck, and routes to the right footpeg. This one is designed to take rain water and other water that lands around the cap and drain it (rather than letting it go into the tank). If you accidentally pour fuel into the surround around the filler neck, it will also run down this tube.

The second is a vent tube, designed to let air in/out of the gas tank as the fuel expands/contracts with warming of the air (or sunlight on the tank), and let air in as the fuel level drops (to prevent vacuum lock). If you over-fill your tank and park up, especially if you do it late in the day, the fuel level may block that hole, and when the fuel expands in the next day's heat & sunlight, fuel can be pushed out of the tube because there isn't anywhere for the air to go. The way to avoid this is to not fill the tank beyond the bottom of the filler neck (i.e. - no burping the tank and adding more unless you know you're going to be riding a long distance immediately to burn it off).

Additionally (not important to you, but very important to California-edition bikes and certain US 2006 models), if you overfill the tank, you can also force fuel into the charcoal cannister and into the PAIR valve system, resulting in the entire bike running so rich as to foul the plugs almost immediately. Again, the cure is to not over-fill the gas tank, particularly on the models equipped with the pollution control extras.

Finally, there is a drain for the airbox. This tube should always be capped off (98+) or folded-over and clamped (pre-98) when the engine is in use, and only drained at oil change intervals (because it presents a way for crud to be sucked up into the airbox past the filter and go straight into the engine). It can leak fuel or oil if left open; this is excess coming off the engine oil once it heats up, or from the carbs from overflowing when parked.

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[andy194bikes]

You have two drains coming off the tank.

One of them connects to a tube that runs up to the top of the filler neck, and routes to the right footpeg. This one is designed to take rain water and other water that lands around the cap and drain it (rather than letting it go into the tank). If you accidentally pour fuel into the surround around the filler neck, it will also run down this tube.

The second is a vent tube, designed to let air in/out of the gas tank as the fuel expands/contracts with warming of the air (or sunlight on the tank), and let air in as the fuel level drops (to prevent vacuum lock). If you over-fill your tank and park up, especially if you do it late in the day, the fuel level may block that hole, and when the fuel expands in the next day's heat & sunlight, fuel can be pushed out of the tube because there isn't anywhere for the air to go. The way to avoid this is to not fill the tank beyond the bottom of the filler neck (i.e. - no burping the tank and adding more unless you know you're going to be riding a long distance immediately to burn it off).

Additionally (not important to you, but very important to California-edition bikes and certain US 2006 models), if you overfill the tank, you can also force fuel into the charcoal cannister and into the PAIR valve system, resulting in the entire bike running so rich as to foul the plugs almost immediately. Again, the cure is to not over-fill the gas tank, particularly on the models equipped with the pollution control extras.

Finally, there is a drain for the airbox. This tube should always be capped off (98+) or folded-over and clamped (pre-98) when the engine is in use, and only drained at oil change intervals (because it presents a way for crud to be sucked up into the airbox past the filter and go straight into the engine). It can leak fuel or oil if left open; this is excess coming off the engine oil once it heats up, or from the carbs from overflowing when parked.

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

thxs for the help cyber,but dosent explain why petrol still slowy dripping out of pipe and also why it forms crystals on the pipe.its coming from the fuel vent hose

[md86]

Rust ate through the tube perhaps ......

[Kreylyn]

I'm not sure he is not talking about the fuel sensor leak catch pan. If he is, then there is a leak around that. Replace the 2 rubber gaskets and that should fix it.

If it is the vent line or top hole drain line leaking gas, they have rusted through the tubes on the inside of the tank. Depending on where and how big the leak, that could be alot tougher to fix, since it's not real easy to get inside the tank.

Krey

[Kfreak]

Rust ate through the tube perhaps ......

I'm thinking the same thing. But crystals? Battery vent tube?

[The CyberPoet]

thxs for the help cyber,but dosent explain why petrol still slowy dripping out of pipe and also why it forms crystals on the pipe.its coming from the fuel vent hose

What color are the crystals?

Also: Can you snap some pictures?

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[md86]

"butt crystals" ? What ?

[The CyberPoet]

"butt crystals" ? What ?

Butt crystals only happen in a special class of riders who go north of the snow line during winter and keep riding for more than 2 hours after losing control of their irritable bowl syndrome...

It's almost as bad as cruiser-riders with Chromes' Disease

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[Kfreak]

If you got "butt" crystals, you have a problem.

[andy194bikes]

What color are the crystals?

Also: Can you snap some pictures?

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

the crystals forming on the end of the fuel/vent pipe are white and they are petrol crystals as it dissolves in my hand when removed from bottom of pipe

[The CyberPoet]

the crystals forming on the end of the fuel/vent pipe are white and they are petrol crystals as it dissolves in my hand when removed from bottom of pipe

White crystals would normally indicate primarily hard water (limestone, calcium); fuel crystals are typically golden/clear (clean) or red (rust-stained).

Since the weather in Birmingham right now is well north of freezing, but very rainy

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[andy194bikes]

I'm not sure he is not talking about the fuel sensor leak catch pan. If he is, then there is a leak around that. Replace the 2 rubber gaskets and that should fix it.

If it is the vent line or top hole drain line leaking gas, they have rusted through the tubes on the inside of the tank. Depending on where and how big the leak, that could be alot tougher to fix, since it's not real easy to get inside the tank.

Krey

maybe u on right track.its where the stub is on the float sender unit and thats where the overflow pipe attachs to.the other part of the sender unit is where the wires go in for the fuel gauge. u think theres seals behind the stub. if its that that be a pain in arse to fix. that mean new sender unit wont it??

White crystals would normally indicate primarily hard water (limestone, calcium); fuel crystals are typically golden/clear (clean) or red (rust-stained).

Since the weather in Birmingham right now is well north of freezing, but very rainy

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

maybe the material in the pipe is making them white,u knw the chemical makeup of the fuel/vent pipe?

[The CyberPoet]

maybe the material in the pipe is making them white,u knw the chemical makeup of the fuel/vent pipe?

Maybe. Or maybe you rode while there was still salt on the roads and it got tossed up there with snow or melt-water

I pointed you at the seal I suspect is the likely cause in PM's -- check it and get back to us

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[andy194bikes]

thxs cyber for all your advice,think u might be right and if that the case that means new sender unit and thats expensive,nearly 90 pounds.just one more point seems to drip petrol slowly in the morning(have a little stain on the floor), then hardley any during the day, wont if seal gone be all the time??