Can only ride half a tank...

[Louimart]

I have a 96' GS500 here in Minneapolis. I wont get to ride for another 6 months or so but thought id get started with fixing her up.

One of the main issues I have is that my bike can only ride half a tank and the engine struggles to draw gas in. First month or so I rode the bike, I got stranded on the freeway couple times not knowing that this was the issue. I now know that I can flip the petcock to prime when she starts losing power, but anyone know how I can actually fix this problem? I'd rather not go to the gas station every other day to fill 2.5 gallons up...

Thanks,

louimart

[Badot]

Wouldn't happen to be a CA model, would it?

[Louimart]

I dont think so.

nothing says CA model or anything. just GS500E. Made in Japan.

[Picowatt]

Once is stalls and sputters, have you tried opening up the gas tank cap then try restarting?     Possible clogged vent tube.

[Kiwingenuity]

Clogged vent tube or inline filter - not so much pressure bearing down to squeeze it through when you get to half a tank..

The prime / reserve lines from the tank not swapped?

[Louimart]

Thank you for your input Picowatt and Kiwigenuity.

I'm guessing its a clogged vent tube and the inline filter that the previous owner put in. its like a disk shaped filter and not the cone style.

Would you suggest swapping that out to a certain kind of inline filter?
If anyone has recommendations, I would appreciate it.

Thanks again,

Loui

[idgs500e]

I had similar issues with my GS when I first got it. Fuel starvation with less than 1/2 tank of fuel or extended high speed riding. Engine sputters and dinking around with the petcock in the twists are no fun! The usable range of the bike was also severely reduced. I went through all of the usual items (vents, lines,not filters, rebuilding the petcock, etc.) which helped but never completely solved the issue. I finally integrated a low pressure (<2psi) Facet solid state fuel pump into the system. This allowed me to run a fine filter and suck the tank completely dry. I have the pump # if you are interested. It's not the common Facet pump at every AutoZoo and O'Reilly.

[adidasguy]

2.5 gallons is a little less than the main amount.
4.1 gallon tank has 1 gallon reserve. if you don't fill it all the way to the bottom of the fill tube, you might only be getting 3.5 gallons in the tank (rather than 4.1) and so after using 2.5 gallons you have to go to reserve (no need for prime as it takes gas from the same tube as reserve).

Normally I can use 3 gallons before I have to switch to reserve - then I fill the tank to the max. You hold out the nozzle and fill until you're full. You can't stick that thing in like you do on a car to fill it up.

2001+ tanks have an extra gallon, so 4 gallons there before reserve.

[Louimart]

thanks you adidasguy and idgs500.

So this summer was my first time owning a bike... and I did fill gas like a car the first couple times. then realized i could actually put more in. since then I've been basically filling all the way up to the neck of the cap. not sure how the venting of the tank works but is there such thing as filling up too much that air has a hard time getting into the tank as gas goes down?
I'm getting about 40-45mpg but how about you guys?

idgs500e, the issues you described are basically spot on. how does this fuel pump work? is it a simple bolt on or does it involve some welding?

[idgs500e]

idgs500e, the issues you described are basically spot on. how does this fuel pump work? is it a simple bolt on or does it involve some welding?

If you have done much wrenching then it's not hard to do. No welding, just mount the pump to the underside of the battery box with a couple of machine screws, use 90 deg 1/8" NPT hose barbs and route the fuel line that normally goes straight to the carbs to the pump inlet, and the pump outlet to the carbs. Wire the pump to accessory power with a 2A fuse. If you haven't done much with fuel systems get an experienced friend to help. Triple check everything and use good connectors for the electrical. No amount of fuel leakage is acceptable, and with a pump even the smallest leak becomes a disaster quick. I'l take some pics tonight.

The pumps are small: http://www.aircraftspruce.com/catalog/eppages/facetpumps.php


The key is to use a very low pressure pump, so as to not overwhelm the float needles and flood the carbs.

[yamahonkawazuki]

2.5 gallons is a little less than the main amount.
4.1 gallon tank has 1 gallon reserve. if you don't fill it all the way to the bottom of the fill tube, you might only be getting 3.5 gallons in the tank (rather than 4.1) and so after using 2.5 gallons you have to go to reserve (no need for prime as it takes gas from the same tube as reserve).

Normally I can use 3 gallons before I have to switch to reserve - then I fill the tank to the max. You hold out the nozzle and fill until you're full. You can't stick that thing in like you do on a car to fill it up.

2001+ tanks have an extra gallon, so 4 gallons there before reserve.

Can also get a tad extra using the technique addymentions, but ALSO keeping bike level. either centre stand  using feet while on it i.e straddling it. idk why maybe it was trouble with my nozzle but had ridden with reserve on for most of my gs days. thousands of miles on 5 bikes. was fun lol

[adidasguy]

Our bikes and most bikes are designed for gravity fed fuel. That works just fine.

A pump would be needed...
1. If there were pinches in the fuel lines
2. You severely over jetted the bike so it requires far more fuel than normal.

Normal fuel issues are often due to:
1. Dirty frame petcock
2. Dirty filter screen in the tank
3. Blocked reserve fuel line.

Switching to reserve after about 3 gallons is normal for 89-00 size tanks. 4.1 gallon tank of which 1 gallon is reserve.
When switching to reserve, use RES rather than PRIME.

[Louimart]

so I took bits and pieces apart from my GS ... upon removal of the tank, I realized who ever did some work on it before flipped the tank petcock around. instead of being able to access the on/off screw from the right side of the tank using a long flathead screw driver, I had to access from the left with barely enough room to get it turned off.

hoses pinched... flipped tank petcock... could very well be the problem.

after the holidays, I'm going to redo the fuel lines and carbs.
I have a V&H exhaust with i think the stock air intake.
is it recommended that I pair the V&H with a K&N lunchbox??

Sorry if i'm asking information that readily available on the net...
I appreciate everyones help and input!

Loui

[adidasguy]

Have put V&H on bikes. No need for a lunchbox. To many it is a fad to do that. To others the lunchbox causes more problems and is a waste of time.
Sewap the exhaust. You'll be fine. Then decide if you want to change the air box. Do one thing at a time so you know what effect the thing you did has on the bike. Change 2 or 3 things at once and if you have issues you have no idea what caused it.