Do i rejet with the HMF slip on? Does anyone have pictuers and is it a good pipe

[yellow400]

I wanted to get a HMF slip on for my 400ex. But do i have to rejet, and is it a good pipe. Does anyone have pictures of one ont their 400ex

[flaneledholes]

Its a good pipe... I payed $270 for the polished aluminium(sp) version and I asked them to send jets for my air box set-up and they did... I reccomend it if you ride where you arent going to be making people mad... Other wise look into the fmf q... Trust me you dont want the cops called on you...

[yellow400]

Originally posted by flaneledholes
Its a good pipe... I payed $270 for the polished aluminium(sp) version and I asked them to send jets for my air box set-up and they did... I reccomend it if you ride where you arent going to be making people mad... Other wise look into the fmf q... Trust me you dont want the cops called on you...

How much did they charge to send you the jets with it??
ANd i think that i'm going to get mine powdercoated red.BUT I DO NOT HAVE ANYOTHER MODS......NO aftermarket air filter or engine mods at all. So would i still have to rejet with it? Also it said that it adds 4 horse power on the bottom end...is that true???

thanks

[flaneledholes]

The jets came for free... I got kinda hatefull with them and told them I would go get me a fmf and they went ahead and gave them to me... It says 4hp but doesnt all aftermarket companies lie??? It gave around 3 on bottom let me rev a little higher and in my opinion is a great all around pipe...It opened up the 400 in all power ranges... I have a k&n with open air box so I cant answer you on the rejet question... Re-jetting isnt as hard as it seems just take the carb off go inside give yourself some time and a clear work bench and go at it...(you have to have basic carb sense to do this tho like where to put the jets in)...Trust me though it is loud as a mofo...

[TRAIL]

You have to rejet with all exhaust and or air filter changes for maximum horse power. You CAN put all that stuff on and leave it ,but it will run WAY lean . just by taking the stock sparkarrerster out of your exhaust it causes it to run lean (white plug). and a free flowing exhaust(any aftermarket company) will def. make it lean. so yes you have to rejet. dont be scared its easy as tightening a chain, at least to me.

[yellow400]

Originally posted by TRAIL
You have to rejet with all exhaust and or air filter changes for maximum horse power. You CAN put all that stuff on and leave it ,but it will run WAY lean . just by taking the stock sparkarrerster out of your exhaust it causes it to run lean (white plug). and a free flowing exhaust(any aftermarket company) will def. make it lean. so yes you have to rejet. dont be scared its easy as tightening a chain, at least to me.

Yo TRAIL what jets should i buy? what kind do you have. and if i have a k&n with a slip on will the jetting be different than if i just had a slip on and no K&n????
thanks

[TRAIL]

I would go an buy a 5 pack of jets(160-170) and go from there. most people run a 165 main. I have not changed my pilot jet yet.
they are the "13 series" main jets. its about 15-20 bucks for a 5 pack.

[cunderwood]

How can changing a pipe make the bike run Lean? I would go with the fact that a more free flowing exhaust will allow for more fuel and better burn, but the Lean vs. Rich occurs at the intake end not the exhaust. Just applying basic principles. The Air Box lid off will make it run lean cause it is on the intake side and you are getting more air than before.

Chris

[yellow400]

Originally posted by TRAIL
I would go an buy a 5 pack of jets(160-170) and go from there. most people run a 165 main. I have not changed my pilot jet yet.
they are the "13 series" main jets. its about 15-20 bucks for a 5 pack.

yo TRAIL where did you get the "13 series" main jets from, for 15-20 bucks. And after a HMF slip on. K&n air filter, and the 13 series main jets what will my 400ex be like compared to it stock??

[yellow400]

Originally posted by cunderwood
How can changing a pipe make the bike run Lean? I would go with the fact that a more free flowing exhaust will allow for more fuel and better burn, but the Lean vs. Rich occurs at the intake end not the exhaust. Just applying basic principles. The Air Box lid off will make it run lean cause it is on the intake side and you are getting more air than before.

Chris

yo cunderwood you said that taking the air box lid off will make it run lean. but what about a k&n air filter with my slip on? then will it be lean??