Forums 🚥 PiT STOP 🔧 Hyosung Technical Help Put some upgraded coils and sprake plugs on my bike now goes 64 Reply To: Put some upgraded coils and sprake plugs on my bike now goes 64

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North UK

The bike is VERY lean, almost dangrous to the piston rings  (if piston rings start to wane – you compression drops bad and it will never be as fast as it used to be)

Heat also makes the valves tighter clearance wise , so ofcourse that will mean you will need to do valve clearances much sooner than later.

Now then, let’s deal with the fuel situation….
– Do this mod below or let your mechanic do it

[Tutorial] How to adjust Carb Slide Needle (Tuning) – Hyosung GV & GT 125/250

It must be done.

The plugs have a sooty black ring, it suggests the carb does get some fuel to idle.

The white center is very white, i mean white! – that means its not getting enough fuel when you’re “riding – whatever mph on the street”.

What jets are in it ?  You should have already fitted the jets i sent you 90 and 92.5

or  92.5 x2
or 92.5 and 95  (max)

Also if you or anyone has ever touched the carb, please ensure the float height is 7mm (not less , not more)

If the float height is affected in anyway , it will affect “riding, idling, starting” .

Follow above early replies for intake air system as extra air leaks near the airbox or manifolds or manifold orings will overheat the bike a bit and lean out the plugs.

Your own air filter is fine , that’s why i did not mention it. It’s brand new.

See how you get on fella, keep us posted 🙂

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