My dealer gets $129 for CDI boxes that eliminate the rev limiter. I was told a local ATV shop (Tom Miller Motorsports in Huntingdon) can take the stock box, modify it and make it like the aftermarket boxes for $90. Thats what the previous owner of my '99 400EX told me he had done. Now a guy I ride with has a '01 400EX and wants his box worked on or replaced. Does anyone know what they do to them to delete the rev limiter? Do the boxes use the spark from the coil to know what RPM it is at? It would be great if we could find out how this is done and be able to save some dollars.

 

go to a honda dealer and order part#30410-kce-671
it is the cdi box for a xr250. it cost about $40-$60 depending from where you order from. the above part is the same exact one that white bros and others sell you for over $100.
good luck.
ron

 

Go to http://www.ctracing.com They sell the CDI hi rev ignition module for 95.00

It works very well, I have been using it for over a year and a half now. No problems....

 

Ronhonda,
Will the box your refering to plug right into the 400EX or will it need to be modified? Does it delete the rev limiter all together, or does it raise it to a higher RPM?

 

it plugs right in and it gives you another 1200rpm before the limiter kicks in.
sorry took so long to respond.
ron

 

I've got the xr250 cdi box and it works well when warmed up but starting it cold is hard. I normally start it with the stock cdi then after it warms up I pop the xr250 box in.