125SX to 200SX conversion?

[Cr85RaCeR607]

What is involved in making a 125SX into a 200SX? Is it as simple as putting a 200SX head on the 125?

 

[Crash217]

besides just the piston, cylinder and head.... you need the pipe, crank, con rod, cdi box and probably a couple other smaller things...

I thought about doing it awhile back, but started adding parts up and figured it wasn't worth it for my intentions with the bike.

 

[elf]

Here is a full list of the parts you would need.

Cylinder
Head
piston, ring
cylinder studs
Crank
CDI
Stator
Flywheel
Head stays
Misc PV parts
PV governor
Gearing
Pipe
Silencer


Unless you have a dealer whos willing to cut you a good deal on the parts it gets pretty expensive.

 

[94ruck]

or you can buy a motor on a parted out 200 on ktm talk, replace the 125 head stays with 200 head stays as the 200 is slightly talller.
we did this to our 125 sx...and we put in an exc motor...6 speed wide ratio tranny...works well everywhere but for mx you will want the close ratio...we kept the bigger 125 carb and black box(and reeeds) so essentially we have a wide ration 200 sx

 

[KDXfile]

The easiest and cheapest way to get one is to sell the 125sx and but a 200sx. They sell for less than the exc's and you may even find a new leftover cheap somewhere.