Reply To: Jetting a GT125R – 2017 ..?
The BDS26 carb has ability to power even a GS500 or maybe an old suzuki i4 (inline 4) with 15 pilots (up to 600cc maybe) , but 30 pilots ? Even the carb 250cc Hyosung is perfectly fine with 20 pilots it uses, mixtures on the 250cc would usually be 3 turns or little less from factory.
Not ideal i know. All stock carb bikes can be tuned 😉 – – If the 250cc (250cc?) can live with BDS26 carbs and same airbox & same air filter, i don’t think a 125cc will ever max out the capacity of the carb, so factories fit smaller jets. And sometimes downtune (downgrade?) the carb to meet 14HP laws in some countries. & emission control (Euro 3 crap)
However i do KNOW , using 250cc intake pipes on a 125cc engine helps with throttle response! (250 intake pipes have a bigger hole) and is much shorter , so carbs are much closer to engine with less travel around the manifold bends for air.
The 250cc airbox is required for this but its okay , its a little deeper than 125 (more room inside for air)
Have you perharps tried size 17.5 pilots ? and check your spark plug colours (from new or fresh clean)