Beginner Exhaust questions.

[PipeMePlz]

OK. Im new to this so, I need a little help.

I want to pipe my 05' 400ex. Money is an issue. So i have a few questions.
1) Will a slip on give me way less power as apposed to adding the header?
2) Would i need to adjust my jets with just a slip on and new air filter?
3) Is it just better overall to go with whole system (filter/jets/header/pipe)?

Any advice would be greatly appreciated!

[rooster300ex]

Your gonna get alot of opinions on this.

If money is an issue I would go with a HMF Slip-on. Yea a larger headpipe is gonna give ya lil more horsepower when jetted right. Yes you will need to rejet after adding slip on & more free flowing filter. If not your fuel/air mixture just won't be right. It will be running lean, which isn't good. It creates more heat.

[amonomous]

Alright here you go

1) Yes it will give you less power
2) You do need to change your jetting
3) Thats pretty much up to u, u can just do it in incriments if u want but it doesnt matter

[bwamos]

I would agree..

You will get less hp w/o the header.. but being that $$$ is an issue.. get an HMF Slip-on and add a WB or FMF header later. ;)

Yes, you definatly, absolutley will need to rejet. (thats a good thing, more air + more fuel = more power)

When you buy HMF they can send you a reccomended jetting setup. It should get you very close.

[Chin_Chilla]

i got complete exhaust very complimentary on ur stock to mild tuned 400EX. Gives great power and huge torque. If i were you id get the complete exhaust instead of 1 part at a time, its cheaper and u get what you want faster. check out my thread:

http://www.exriders.com/vbb/showthread.php?s=&threadid=244723

thanks, Chin_Chilla!

[idontknowwhoiam]

There was just a pretty BIG thread about a header being a waste of money if u have a stock motor..i cant find it right now but i know i looked at it

[04TRX400EX]

1.) The last post kind of hinted on the real deciding factor. You really only need to do a full system if you are going to get into the internals of the engine: cam, bore kit, etc. The stock 400EX header is actually one of the better ones out there. It is pretty free-flowing and the slip-on alone will be a great start to performance mods in combo with a high-flow filter. You'll probably pick up around 3-5hp with a slip-on and 6-7 with a full.

2.) Yes you will need to rejet the carb. With a less restrictive exhaust, you will be running too lean which is bad. All you have to do is rejet the Main Jet and possibly adjust the air/fuel mixture screw. It really isn't hard to do but is necessary.

3.) As for overall, like I said in #1, it all depends on what you are going to do later on engine wise. If you are going to keep it pretty stock, a slip-on and a filter is all you need. If you want to do more internally, than I would say to go with a full. Money considered, a slip-on and a K&N gets my vote. Jetting is required for both situations.

BTW, once you uncork the engine a bit, if you really want to be faster, aftermarket suspension is the key. It's just $$expensive$$