I just order one and its almost here. I was woundering how its gonna sound and any of you have one? Do i have to take off my gas tank to get to the carb? And is it ok just to put on the pipe and see how it sounds first before i rejett? thanks

 

i would rejet it. put in a 40 or 42 pilot jet. put in a 155 or so keihin mainjet.

they are great pipes in my opinion.

 

Thanks cals how will it sound you think? for sure do i have to mess with the pilot jet? all i will add is a K&N air filter and the pipe is commin with a 165 jet how will i have to put it at 155 will it be hard? thanks for the help.

 

HMF is an awsome pipe, on the loud side though. I put a 165 main in my Z, and turned the air screw out 1/4 turn, really woke up the bottom to mid.

 

No, don't mess with the pilot jet. Yes, you can put it on and listen to it and even ride it forever without worrying that your engine is going to get messed up. Re-jetting will make it run better- but with just a pipe and filter, re-jetting should deffinately be done for best performance but your only going to change a couple of jet sizes so it's not that big of a deal.

There is a nut on the bottom of the carb, remove it. now take a 6mm socket (I belive, I know a 1/4 socket will work) and stick it up the hole you have just made. It will go onto the jet, lefty loosey, take it out and put the new one in. Make sure your gas is off the entire time.

JP

 

Thanks alot guys your great! do you think 165 is to much if so can i put some holes in my airbox or what best thing should be done? And one more question both my buddies have 400ex stock should i be wasting them now?

 

you can put the 165 in if you want. however, it just depends on on much power you want to gain. you will have more upper gear performance with a 152 or 155 and the lid on than with a 165 with the lid off and a K&N filter.

 

Buy some ear plugs. You're gonna need them. Great pipe, but loud as a ****.

 

Leave your pilot jet alone. Put in the 165 main. A keihen and Dynojet jets are way different. A 165k and a 165d are completely different sizes. You could leave the stock jet in at the expense of your valves in the long run, and when I say that, I mean the very long run. You would lose power and throttle response, if anything, if you didn't rejet, but it won't be overly drastic. However, you'd gain a good dose of power if you rejetted with that pipe and filter combo.

 

Cals400ex, what in the world are you talking about. I am sure that you have the best intentions man, but geeze, your gonna get this kid ALL messed up. You cannot gain power by rejeting. If you could, then we would all jet up everything to flow just straigt fuel. It really bugs me when people list there mods and they add jetting as a mod. It is not a modification, it is a tuneing tool used to make your engine run as clean and cool as possible. If it is jetted right, it just means that the engine is running at it's potential. You cannot gain power by jetting an engine correctly, you can only loose potential power if it is jetted incorrectly. You can gain SOME responsiveness by going to an aftermarket jet kit but again, you are simply giving the engine the perfect amount of fuel for it to run at the potential it already had and no POWER is gained. But then those kits cost $50 for something that is really nothing but advertisement.

JP

Don't take my capitalized words as anger, I was just putting enphasize on them.