kfx 400

[fuller01]

i just bought an 03 kfx 400 paid $1300 the bikes been rode but its not in bad shape it needs tires and a timing chain i wanted to know if any one has one with the big bore kit in and how does it hold up 2 the new yfz450

[cr480r]

My buddy has one with a 435 big-bore and a stroked crank making it around 450cc. He has stage 2 hot-cams and a pipe also. His bike runs neck and neck with a TRX 450, which is a huge improvement over stock. The TRX is stock with just a pipe and filter. I'm sure there is more you can do to one. Like a rev box, carb, porting, higher compression, Etc.. $1300 is awfully cheap, Did you get any paperwork or a bill of sale at least?

[fuller01]

he bought 2 ninjas and wanted out of the note but ive got paperwork on it it was a friends bike

[z400nate]

The athena BB 434 kit is IMO the best kit you can put on those quads. They are probably as reliable as stock, and come as a kit with another cylinder so you dont have to have your stock one bored. With that kit, some cams, pipe, filter, ignition/rev box, and proper tuning with possibly a bigger carb, you can run with 450's all day.