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kory
11-20-2006, 03:22 PM
i just bought a hmf exhaust for my 400ex its a slip-on so i didnt think i had to re-jet it do i need to or does anyone think it would be a good idea to also does it do anything bad if i dont re-jet it thanks
Reggie44
11-20-2006, 04:34 PM
On your 400ex, if all you have done is put on the slip on, it probably doesn't matter if you rejet it or not. If you go with a k&n filter along with the slip on, I believe I would. I have an 02 ex with a slip on and k&n. I've rode with a 152 main jet, and never had any problems at all. It will give you a descent performance gain for just the few extra dollars. If you decide to rejet it. take off the nut on the bottom of your carb using a 17mm socket, then (i think it's a 9mm, can't be sure) and reach up inside to take out the main jet. Be sure not to overtighten when you put in the new one. Hope this helps
kory
11-20-2006, 04:52 PM
so your saying because i have a k&n i should re-jet it or having the slip on and k&n i still dont need to re-jet it
4TraxRider
11-20-2006, 04:57 PM
A filter won't make much of a difference in jetting. Running with or without the airbox lid is the deal breaker. If you put a slip-on on, and remove your airbox lid then you'll need to rejet. If you just put a pipe on and left your lid on, you can probably get away without re-jetting, but a jet is on a dollar or two, why wouldn't you to do it right and get the horsepower you payed for?
kory
11-20-2006, 05:27 PM
sound reasonable but i have no idea about what jets to buy and how to go about putting the new ones in i never uselly **** around with that stuff and your saying its bad to ride without your air filter lid on because my buddy has a slip on and k&n but never re-jetted his but rides with his air lid of and that things has had some problems in the past and i just never did it because im in water sometimes and didnt want to get water in it
kory
11-20-2006, 05:28 PM
o ya and re-jetting will make a difference in horespower i always thought it didnt do much you just needed to when you go a pipe
ThorR88
11-20-2006, 05:35 PM
when i had my ex i had a hmf slip-on with a K&N filter and i never re-jetted it and it ran awesome