Question about 2001 Hyosung RX 125

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I changed the carb on a hyosung gf125,but now when it starts it revs its guts out,wots wrong?

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  • stuart_geary Jun 22, 2009

    this can't be the case, its an identical carb and was runing sweet be for the change over.

  • stuart_geary Jun 22, 2009

    the orginal carb was weeping fuel coz of a dodgy float, so i changed it with identical carb, all connections are the same and the pin is in position, do i need oil in the cap that houses the spring above the pin that sits in the carb?



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Hi there,

The airbox, carb, and exhaust systems are balanced with one another from the factory. If you make a change in one area, you will most likely need to make a change in another too. In particular, adding the cone air filters probably increased your airflow through the system. If so, that may require rejetting the carb in order keep the air-fuel mixture correct.


Posted on Jun 22, 2009

  • Mukesh Kumar Jun 22, 2009

    Can you please explain the exact problem you are facing...??

  • Mukesh Kumar Jun 22, 2009

    Yes, you need a oil cap, to control the oil flow.



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Starts runs wont accelerate

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My hyosung wont start, it was running fine until it was parked in the shed for approx 3 months, now it wont start! It seems like a fuel problem, it will start and rev when we squirt fuel into the...

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It sounds like the carbs are not getting fuel to the engine. This is common with the fuel that we get now. the fuel is not stable and can gum up quickly. I have seen carbs become clogged in as little as 60 days.

The first thing to do is drain the old fuel out of the tank and the carbs. There is a drain screw at the bottom of the carbs and you can drain the fuel out by loosening the screw. Make sure that you are carefull when draining the fuel out so that you dont have excess fuel leaking everywhere. I usually put a small container uinder the drains.

Syphon the fuel from the tank and replace with fresh fuel.

After all this is done try and start the bike and run on choke for a while. the fresh fuel can help to flush the old gas out. If the bike does not run properly the tank and carbs may need to be cleaned. The carbs are very detailed and should only be worked on by a qualified technician.
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