1980 GS 750 not sucking fuel when hot

[mrbill5491]

Having the same bike and I've had the same problems at one time or another. Lose the in line filter period and I seem to have to changed out the petcock about every 10 years (seems like its life span anymore) rebuild kits really don't work ( been down that route too). It just ain't cool when passing a semi uphill and you just get by him and back into the lane when the bike sputters out of fuel and all you see is the grill in your mirrors cuz your bike died. New petcock time. Check your rubber boots from the carbs to the intake side of the head, especially #2! A slight crack will cause you to lose your vacuum, yeah you got it and your fuel flow. Make sure you have the stock clamps and they are good.

[JTGS850GL]

If it happens reliably then you should be able to narrow it down. Drive it with the gas cap off and see if the problem goes away. Just make sure the tank is not full. If the problem goes away then it's the cap vent that's clogged.

[ericeder141]

Good call on the fuel filter took it out put in new gas line runs like a champ again. Thanks everyone Cant believe it was such a simple solution.

[Steve]

The reason we blame a fuel filter so often is that most of them are designed for cars with pressurized fuel systems. The only "pressure" in our system comes from gravity pulling it down a few inches, which is not enough to push it through the rather restrictive filter elements in the automotive filters.

There is a filter in the fuel tank, on the inlet to the petcock. There is another filter in each carb, at the inlet to the float valve. If you absolutely insist on having an external filter, get one from the lawn tractor department at your favorite "big box" store. Many (most?) lawn tractors have gravity-fed fuel systems, too, so the filters will work on the bikes.

Another disadvantage of having a filter in the fuel line is that it is a rigid portion that might be in an area that needs to bend. My fuel lines dont have many places they can go straight far enough to put a filter in, as they are curved in one direction or another for virtually their entire lengths.

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