Loosing power on highway - still gas in tank.

[jonasa0601]

Hello!

This is my first post here. I just bought a 1997 red GS500 a few weeks ago, and had oil filter, air filter, brakes, suspension, etc fixed.
Yesterday I rode 50km on the highway with 110 on the clock, and there was no problem. Then today I rode the50 km back home, and suddenly  the engine started loosing power, like when she's out of gas. I pulled over, and activated reserve tank. Rode on for a while, but the problem came back a few minutes later. I carefully rode on and found a nearby gas tank and filled it up. It could consume 10 liters - which means there must be around 7 liters left in the tank, right? So it is not because she was out of gas? Anyhow, after I got fueled up, the problem was gone. Afterwards I tested the bike and drove up to 160 on the clock, and there was no problem at all.

What can be the cause of this? I'm going on a 3000km trip soon, and I would love to solve these kinds of problems before I go

Best regards, new GS'er - Jonas

[smokestack]

If it starts happening again, try switching to PRI and see if the problem persists. The vacuum feeds from the petcock are known to have issues, especially if left sitting for a long time.

[Atesz792]

Also try opening the gas cap then closing it and riding on to see if the problem persists. If doing so solves it for a while, you gas cap vent might be blocked and need cleaning.

[jonasa0601]

Had same problem today, but switching to reserve solved it this time. Weird.

While I'm at it, I have another problem:
RPM go up when I turn my handlebar left or especially right. I figured it is the throttle cable needing adjustment. The throttle adjustment screw(or bolts) at the handlebar is tightened to the max, so I can't loosen the cable length more. I guess I have to adjust it another way. How do I do this?

Best regards, Jonas

[chornbe]

There's likely more adjustment available at the carburetor mounting bracket. Pull the tank and eyeball that. There might be a mid-cable adjuster to cheeck out, too.

[jonasa0601]

This problem occured after the bike was at the mechanic to have a few parts and filters changed.

The cable should be adjusted right - I dont't think they have adjusted the cable screws/bolts, so maybe it's the routing that's a bit different? Should I still try to adjust on the middle or at the carb?

[Janx101]

When you lift the tank. . There is a crossmember above the engine that the cables pass over, usually there is an ADJUSTABLE cable tie that loops around the crossmember and throttle/clutch cables.... make sure this is fairly loose!  .. its there to keep them roughly centralised, NOT to pinch them down tightly....

I tightened mine up a while back because 'it was loose' and suffered instant turn bars/throttle gain..  loose again and the problem disappeared. ..

Not saying it can't be another issue but it would be one of my early checks!