KDXRIDER.NET

Hello,

i have a kdx125, but i want more power for a better off road experience.

The model is from 1992. I heard that i would be able to fit a kdx200 engine in the frame, but would it also be possible to only put the 200cc cilinder? I dont think its possible, but anyone that knows it for sure?
it would be a lot cheaper to only have tp put on the other cilinder.

If thats not possible, does anyone know how i can get 25-30 horsepower on the bike? other exhaust?

Thanks in advance to anyone who can help me with my build!

Short answer is no
Long answer is anything is possible as long as you have 30 or 40 years experience behind you, to fit a kdx200 engine you would then need the exhaust,airbox,carb, CDI the list goes on
To fit a 200 cylinder you would need to be a mechanical guru

To take about horsepower only is to not understand the importance of how its delivered and at what RPM
Your best option is to have your kdx125 running and jetted perfectly which few 2 strokes are, the kdx125 carb is the same as my kdx220sr Keihin pe28mm and there is a good chance the emulsion tube needs changing but finding needles for that carb becomes impossible and I've spent countless hours trying to figure out alternative needles including buying many kx80 needles which do not work

Any crazy mods you do on these kdx's only results in a lower resale value and then becomes a money pit

The KDX 125 is based on a 91-92 KX125, so I doubt that a KDX 200 cylinder will easily bolt on. If the base gaskets are the same part number, then with some work and some parts swapping, it might be possible, but I would imagine you would have to clearance the crankcase even. Transfer port matching, power valve linkage issues perhaps, this is all unknown as this is not a common engine to most readers here. We never got that bike in the USA and more members here are from the USA/Canada than not