Hey i have a 400ex that is stock exept for a k&n filter and jet kit. Should i get a full exaust or just a slip on silencer. by the way if i did get just the silencer would i have to put a stage 2 jet in instead of just the stage 1. thanx

 

With stock compression go with a slip on, otherwise the motor goes "flat" on the top end. I'm not sure what you'll need for jetting since it's effected by so many things (altitude, temp., humidity, etc.). You'll probably have to use some trial & error there.

 

yea, I say go with the slip-on only too. the 2 big magizines did shootouts with many different pipes for the 400ex, and from the dyno charts it looked like the slip-ons were getting better numbers than the full exhausts.
I got a pro circuit slip-on for my 300ex, and I used a stage 2 jet kit, but I have the air box lid removed. the instructions should tell you what to do. for me it was stage 1 with the lid on, and stage 2 with the lid off.

 

bye word of mouth and shootouts i hear that white bros e series pro meg is the best. 3 shootouts i have seen proved it to be the best one, it has the most hp gains its a spark arrestor and its quiet. im going to get the full system and put the header on when i do engine work down the road so i dont ruin it now, plus it doesnt give you any more hp on the stock engine.

 

Do those things also apply to the 300ex? I was thinking about the same things.

 

The Curtis Sparks system was .2hp Above the White Bros.

Mac

 

If price is a concern (and it almost always is), you could start out by doing modifications to your stock pipe. Read my article "Internally Derestricting Stock Exhaust" for info on how to do it. I recieved some noticable gains on bottom and mid-range power, with a minimal noise increase. If you can't see it on the topic list, just do a search on it.