Hmf Slip On - Jetting In Mn.

[thomps6s]

I just bought a HMF Slip On and am supposed to be getting it tomorrow. I live in Northern, MN, near Duluth. I am wondering if I will need to re-jet after putting the HMF on. I have a stock 04' 400ex. One of my friends put a full system on his raptor and never touched the jetting, he hasn't had one problem, no popping or revving issues. I am hoping I won't have to F*&k with anything. Anyone have any similar experiences.

[k2-dawg]

Here's what HMF recommends.....

HMF Jetting (http://www.hmfengineering.com/jetpg.html)

[skemp]

And that is ridiculous. With just a slip on, you won't need any more jet than a 155. But to answer your original question; yes, you will need to rejet after putting on the slip-on.

[speedy400]

I'm also from mn, south central mn though, my dad also put a HMF full system on his rappy and yes that person should rejet for the max power. You should also rejet, maybe bump it up to a 160 tops, if the spark plug is then black, put it down to 155 ..ext. good luck, I love my hmf slip on..I have a powerbomb header also-darren

[MNTNMAN]

With just the slip on and stock air box, I ran a 150 MJ and 3 turns out on the fuel/air screw at about 1500ft elevation.

[thomps6s]

Put the new HMF slip on silencer on my wheeler yesterday. It is Fu@*!ng loud - The sound is awesome. I love it. Power feels great - real smooth across all ranges. I Highly reccomend this pipe. Hopefully I can post a picture soon with the bright yellow powdercoated pipe on my red 400.