HMF pipe so what jetting?

[jiggaman2401]

Hey i bought an HMF slip on today my 400 also has a K&N filter with the lid on what do you guys think i should up my jets to? Would a 160 be good? Should i also turn out my air/fuel screw? Thanks

[underpowered]

i runa 165 main of my 426 which is a little rich. I would say a 155 of 158 should be good, a 160 may work depending on weather and where you live.

[jiggaman2401]

Yeah i live in ny and its a little cold right now so ill give it a try when i get it.. thanks

[pead_24]

im running a 158, with HMF slip on, K&N with outerwear, and lid on

[jiggaman2401]

how do you like that HMF slip on? Do you have a silencer on it? IS it extremely loud?

[400EX QUADER]

I have a HMF slip-on and a k&n with outerware with my lid off at the dunes and on riding trails. A keihen 155 works great!

[pead_24]

Originally posted by jiggaman2401
how do you like that HMF slip on? Do you have a silencer on it? IS it extremely loud?


If your talking about a quiet core???? no i dont have one, its loud... but also sounds great:D

[jiggaman2401]

Nah not the quiet core pipe i ordered the Sport quad pipe.. I thought it might come with an end cap silencer?

[400EX QUADER]

no the quiet core goes in the sport pipe it's like a spark arester but it makes it quieter. Without it it's loud and with the quietcore it's loub but not too bad. Sounds great though.:D

[Plante400]

since u are all on the hmf subject does anyone have a slip on, onto the stock headpipes?

if so how does it fit.,. my pc4 fits like Chittt

[jiggaman2401]

Originally posted by 400EX QUADER
no the quiet core goes in the sport pipe it's like a spark arester but it makes it quieter. Without it it's loud and with the quietcore it's loub but not too bad. Sounds great though.:D

aaahh alright thanks for the info..

Plante- Ill let ya know how mine fits on thurs when i get it.. ITs going on the stock head pipe..:macho

[400EX QUADER]

It fits great on my stock header.

[underpowered]

mine works great on my stock head pipe.

[Plante400]

Thanks hoomyyyss

[WingerDingerEX]

fits excellent, sounds good (loud), good low-mid end with the lid on, good mid-high end witht he lid off.
main-155
pilot-42
needle-3rd position from top

[red4ooex]

start with a 175main, 42 pilot and back air screw out 2 turns this will be a start depending on where you live.

[jiggaman2401]

awesome great info thanks.

[jiggaman2401]

Well i put my HMF pipe on and im searching there website and this is the info it gives for jetting it..165/170 mainjet 3.5 turns out on air/fuel screw and needle in 2nd position from bottom..I run a K&N filter with the lid on and my elevation is 430 feet.. Would these settings be excessive or good?

[cals400ex]

Originally posted by jiggaman2401
Well i put my HMF pipe on and im searching there website and this is the info it gives for jetting it..165/170 mainjet 3.5 turns out on air/fuel screw and needle in 2nd position from bottom..I run a K&N filter with the lid on and my elevation is 430 feet.. Would these settings be excessive or good?


sounds pretty good, i would just use a smaller mainjet.

[jiggaman2401]

Well i got a 160? Im gonna give that one a shot..