How much performance do these offer?

[RNL]

I was looking at a sparks key, and a FMF header for my Ex. I was wondering how thesse two mods work on the 400. I already have a Lexx slip on, would the header bolt up to the Lexx or would I need a different slip on? Is the performance gain worth the price?

Same with the sparks key. What kind of performance are you gonna see with this installed?

[bigbad400]

the fmf headpipe will bolt up to any slipon. its same as stock just flows way better.

i love mine. especially the sound it makes with my HMF slipon. power is wonderful on the bottom and really lets loose in the mid to top too. but she screams like a v8 when your up there. it a loud mama jama i just ordered a quiet insert for mine. lol

the sparks key is a little bit of a job but its def worth the money. 30 for that and a case gasket for 15 and 45 min in the garage and you should be able to handle it. theres a great write up on that along with lots of other 400ex info on the top of the 400ex threads page. alot alot of people do this one including myself and have bean impressed with it. enjoy

[RNL]

Thanks for the response, the 400ex seems seriously detuned in stock form!

[RNL]

I have a friend buying a nice Z400 Zuki. Would a 400ex with the big 3 and sparks key be equal to a Ltz 400?