slip on exhaust (few questions)

[jake"08"400]

:huh So i am new to this messing with jetting stuff but anyways i got a 2008 400 ex i already got a 42 pilot f/a screw 2.25 out and needle 3rd notch 152 main jet. and i know its prolly rich even though when i pulled my plug its brown not wet and are white from being to lean. and also im bout 800 to 1,000 feet above sea level im in alabama. anyways my question is do i need to go up on my main with just a slip on are should it be fine the way it is at 152. also does anyone else have a hmf performance pipe and how do you like it and how loud is it? thanks for any help...:) o yea and i got a k and n filter and about 6 uni pre filter holes in my airbox. sometimes no lid...and how hard is the install on a new pipe.

[slightlybent47]

Boy the aftermarket guys love it when new guys start looking for power. Removing the air box lid and adding an aftermarket exhaust only gives you a gain of 2-3 hp for a significant amount of cash. Say $250.00 to $700.00 for a full exhaust. The best you can hope for is a small gain in hp and a little better throttle response. If you plan on doing motor work a pipe and slip on can help you, but on a stock motor the gains are small. A sparks key will do more for hp at a much lower cost then a pipe. With the air lid off and a slip on added you only need to bump the main jet up one jet size to be where you need to be. Messing with the needle and a/f screw will only do more harm then good, with what you have done so far. If you are doing motor mods with the added pipe then go ahead but if not save your money and use the stock pipe. You’ll be able to ride in more places with a stock pipe. Just my opinion.

[jake"08"400]

already got the pipe man. and sure it might not give much power but why not get it if you have the money.? and it looks better than that old flat black 20 pound chunk of metal on hte back of it now

[slightlybent47]

Ok that’s fine, just don’t be disappointed when it doesn’t run that much better. It will sound better but you may not be able to ride where noise is an issue. They are lighter then the stocker and help shed a few pounds off the quad. Sorry if I came off wrong it’s just I see so many people buying a pipe for the wrong reasons. If you already have it then go for it, if you do more motor mods down the road it will come into play much more then it will now. Good luck.

[2001400exrida]

jake you will love the sound of that pipe.

slightly bent is slightly wrong. you will breath better with that pipe so you'll have to rejet as stated, you will also gain some horsepower since you're opening it up.

air filter and slip on are the most common mods out there i would say. the sparks key is over-rated. just keep your stock timing and do motor upgrades so you can draw real power out of the motor instead of just advancing the timing.

I bought a pipe and air filter for my 07 and i'm very happy with the purchase. Sound restrictions are rare so let that thing rip it's not made to run with a full blown muffler liek that one that comes stock, that thing is just there to pass emissions standards.

jetting varies. as previously stated about only needing to go up one size, that's simply not true at all.

I put a lexx slip on and a uni filter on my quad and i had to get an adjustable needle in order to get it in tune right. I am running a 40 pilot with a 155 main jet and i'm 3 out on the a/f screw.

it certainly WON'T do more harm than good to adjust your a/f screw and needle. Like i said i was lean with my stock non adjustable needle and all i have is a slip on and a uni air filter with the lid on. I had to buy the adjustable one and go to the third clip setting with a washer shim.

man i'm tired of see bogus advice, people get all worked up and straight up give nonsense for advice.

[slightlybent47]

I figured someone would dispute my opinion, goes with the territory I guess. Just be aware that some of the advice you get on here is from youngsters that have no idea of what they are saying, they are just repeating something they have herd and is not fact. I don’t feel like arguing tonight. Do what you want.

[jake"08"400]

i thank yall for the replys....slightybent its cool man no hard feelings just thout id let you save your time and brain power trying to tell me not to get it cos i got it already.NOW for my question i know i general way of putting it on but is there any tricks are anything to putting it on? any Help id apperciate