Topic Tag


Carby 250 dies when choke turned off


I’ve just got back into a project bike I’ve been away from for a few months and am having issues with idle and revving.

The carbs have been stripped, cleaned and reassembled. The bike startes and idles with the choke on and will remain running if left alone.

If I try rev the engine, the engine will “choke” itself and stall out (die) – choke is still on at this point. When I slowly back the choke off, the engine starts to struggle and will also die, usually when choke is about 80% off. The idle adjuster screw is wound in to give max idle.

Sometimes I can slowly roll the throttle on and the revs will climb, but not much. Sometimes when doing this, when I release the throttle, the revs skyrocket before stalling out.

I’ve taken the jets out and given them another blow out but still get the same thing. Reading through any carb related posts here, I should have a 95 and a 92.5 jet – I can see I  have a 95 and a 9x.5 (I cant make out the second digit). The air mixture screws behind the black bungs were changed when I cleaned out the carbs a few months back. Reading through the carb posts last night, I now see I shouldn’t have touched them – looks like I’m in the abyss. I checked a spare carb that hasn’t been touched and found that both front and rear were wound 2 full rotations out from fully in. I’ve adjusted my air mixture screws to suit – it made no difference to my issue – same problem persisted. I’ve replaced all hose clamps to stainless but most of the hoses are original.

I’ll try put a video of it running.

Any ideas where I should look next?

[Download] GV125 + GV250 Aquila/Mirage Service Manuals & Hyosung Owners Books


Hyosung’s favourite & the first  125 twin to roll out the factory, the GV 125, then followed the GV250 Aquila!

A printed owners manual is a must have for each rider. But hey , the internet is here.  Download the PDFS below…

Don’t forget, the GV250 plus the 125 version shares the engines with GT125 & 250cc Bikes.  Some data is the same.

Here they are…!

📕 OWNERS MANUAL – GV250 Aquila – From 2003 Onwards – CARBY EDITIONS (Carburattor Models)
(Ok for 125cc bikes also!)

📕 OWNERS MANUAL – GV125 Classic – 1998 – 2001 – FIRST GEN – OWNERS MANUAL

📕 OWNERS MANUAL – GV125C – 2002 Model – 2002 MODEL OWNERS BOOK

If unsure or need help with a particular problem ? Post in the “Parts Help section” instead…