I just bought a Roketa KTX 250 WJF. The previous owner had drilled out the jet/jets not sure what he did but plug ran on the black wet side. I cut the converter out of the pipe and trashed the air box, I have a uni filter coming from the local bike dealer. As it sits now after taking care of the exhaust the plug is a little too white. Can you give me an idea on where to start with jetiing.

Also with what's been done above what would you recomend for max top end, and also max bottom end. I would like to have two diffrent setups, so I can have the best of each for diffrent ridding.

welcome to buggynews. that has a cn250 engine so there is a good bit you cam do to it. I would start with a 128-130 main jet, 38 pilot jet. for max low end go 11 gram rollers and a red or white main spring, also a cam will help to, a 32mm carb

for max top end go with the above except for the rollers, the rollers thats in there now should be around 22-24 grams. a heavy slider will work also.

Ok if I am reading this right for max top end I want to keep the rollers I have now and use the same white or red main spring that I would for the low end setup and add heavy sliders?

Probably not much point in doing the cam and carb swap, I have pretty much decided that I am going to use a 1.0 Geo engine and 5 speed and do a swap. I like the idea of having 55 horse and 58 ft lbs of torque. Then I will also have the top end I am looking for. Anybody know of anyone doing something like this on a Roketa?

The guys at work say use a sled engine but I dont want to lose reverse.

now that would give you the best of both worlds. the red or white main spring which is stiffer than stock would help keep it in low gear longer and make it down shift quicker.