Curtis Sparks Racing offers a bolt on hop for the 400EX. It supposedly advances the timing 6 degrees. This is what he says it does:

Sparks Racing has found inexpensive, instant bolt on horsepower!

Our Ignition Advance Key simply takes the place of the stock woodruff key and advances the timing six degrees instantly!

What does that actually do? Well, it peps up the motor. Bottom end all the way through top end is increased.

Response from riders who have tried the ignition advance key has been awesome! This is a must have for every 400EX owner. The key simple to install and works well with stock 400EX's all the way up to a fully built 400EX.



Has anyone tried doing this mod? If so, what are the PROS and CONS?

 

I have been told that it does help the 400 run better. It does make the 400 hard to start if you race Hare Scrambles this would be a problem, but with MX or TT it will help.

 

Could also make it prone to overheating.........