The std 200 is good enough to top 90mph on std gearing on a good day, and will sit at 75mph all day long. The motor characteristics feel more like a DT175 with a big bore kit fitted really. Yeah the std KMX200 is useful with a genuine 26bhp at the r/w, but it's no monster in it's delivery and is very tame with a much less pronouced powerband than a 125 performance 2stroke.
I don't think it would be hard to get 25bhp+ at the rear hoop, from a KMX, and thats about the same as a std 200, but much more revvy! The TM28 from a DT etc does improve performance, and having the cylinder head machined and re-profiled seems to give some good gains too. A DEP silencer would be a millon miles better and easy to service and re-pack, as well as quieter.įor more tuning you can fit the V-force reed block for the KDX200, and a Mikuni TM30SS carb is supposed to work really well, but you won't find a secondhand one easily. The Gianelli pipe is supposed to be the best pipe for top end power, but i think you get very little below 7k, and it's noisy especially with the tiny Gianelli end can as well.
The KIPS system lives in an oily sticky gungy world, so if your bike has done a few miles, then id take the head off and remove the KIPS valves for a good de-grease and de-carbonize the cylinder head, piston, and KIPS chamber and passages. The KIPS valves were made of alloy, and the cure was to change to Steel valves, which would not break. The operating mech, would then try to open or close the stuck valves, and snap the valve spindles below the rack and pinion gears. Early bikes had problems with the KIPS valves getting stuck due to carbon build up, and they would seize the KIPS valves in the barrel. The later KMX's were never restricted by the power valve KIPS, and this should activate at 6500rpm.
#Kawasaki kmx 125 big bore kits full#
The std bike should spin a dyno to 20-21bhp at the back wheel in full power form on a healthy motor. Either remove the exhaust restrictor washer from the front pipe, (has 3 spot welds like the NSR125), or fit a big one or Gianelli expansion chamber.