With a sparks advance key, will I have to re-jet again?

[nikejoe]

I was just wanting to make sure. The instructions spark's give with this are a joke. I searched this site and found out everything I wanted to know except do I need to re-jet. I am runnig the mods below (e-series slip-on, alum air-box no lid, K&N filter). I am at about 800 feet above sea level and right now I have a 155 main and 40 pilot with needle in stock position. I did a plug check and plug was grey. But quad runs better than it ever has. Now I am going to add the spark's key and was wanting to know if I will need to go to a larger jet? Any ideas would be appreciated!
Thanks!!! :eek2:

[cals400ex]

you really shouldn't have to rejet. i would see how it runs and then go from there.

[400extracc]

i asked the same question to sparks when i got mine. they said no

[SHADETREE101]

we have the same set up on exhaust and breather. i already changed the timing with spaks key. it didn't need any more jetting. it runs perfect and has a little more power. i raced another piped 400 and it pulled him pretty easy, and i out weighed him quite a bit. throw it in and run it for all it's worth.