don't want to start any stinky business with exhaust OPINIONS.. just a couple simple questions that I could not find an answer to..
I noticed HMF slip- on shows only 2.5 HP increase- and it looked like this was AFTER all the free mods- can anyone confirm?? if it is really after jetting and air box etc.. then the slip on would only be like 1HP maybe- not worth $$ to me
also I am looking for low end only-- does a full sytem help better than jsut a slip on for torque only- some say the 250 head pipe with slip on is better for torque??
lastly I can't find anyone with any experice with FMF slip on- I like FMF from past experience- but have not heard of how they work on KLX250...
Thanks- after 100 miles on the new bike.. me likie

 

Mike, you already know you are steppinginto a mine field here, but let me weigh in before it gets too ugly. Before I say anything, though, let me state that I have the full Muzzy system, but I am of the opinion that all brand are equivalent from a performance standpoint. The only differences (again, IMHO) come in the look and sound that you might be looking for. Even then, I can say from personal experience that the Muzzy & Big Gun, at least, sound very similar.

With that said, I can tell you that I agree with what you have heard about the low end. I think from a back pressure standpoint, that the smaller stock head pipe should result in a little more torque down low. The larger header available with the full aftermarket systems should help on the high end, but probably cost you a little down low.

Other will no doubt disagree with me, but I also agree with you that the performance benefit from the exhaust system is lower than any of us would like to admit, and is almost certainly not worth the $$ that we have put into the aftermarket pipes. Saying that, though, I don't regret my decision to replace the stock exhaust. While the reported HMF numbers do include all of the free/cheap mods, the fact of the matter is that it is best to do all of the stuff together. There are some of the free/cheap mods that you can't or shouldn't do unless you do the exhaust as well (rejetting), and some that you don't really get the benefit from unless you do the exhaust (airbox mods). I look at it like this - the free/cheap mods aren't really free/cheap. The basic mod package boils down to the cost of the exhaust plus some free/cheap stuff.

Good luck in your decision making. If you want my opinion, I would keep your stock header and go for an HMF slipon. You will have to modify the rear-most mount point with a 1/2" to 1" spacer to keep the pipe from hitting your fender. Other than that, I haven't heard any knock against the HMF.

Let the flames begin.

 

You're thinking about it the wrong way... Without a free-flowing exhaust, the other mods can't do their job. No, you won't get 10 horses just by slapping a new pipe on. But you won't get 10 horses unless you put the new pipe on... Does that make any sense? You can do the other mods, but they won't work unless you de-restrict the exhaust. Now, you could do that by cutting off the catalytic and muffler, and welding on some ghetto can... Or you can spend the bucks on a nice system. Both will probably net you the same effect - a free flowing exhaust.

 

thanks CW and Kawi,

I understand what yoiu mean- the other modes are a waste without a better exhaust.. do you guys know if a slip on for a 96-2001 KLX250 would fit the current model?? I thought this was the same bike from overseas for years- but then why would they say up to 2001.. anyway I want to say that I appreciate 99% of you guys- this forum is a lot less sensative than truck forums- God forbid yoiu say anything negative about a truck- fact or not- you will be hammered to death..

p.s. Florida riders- i checked out the seminole/big cypress track.. to me ( novice) the place is awsome and priced right- two seperate tracks and trails- only an hour from Ft. lauderdale

 

No the older model KLX250's exhaust wont fit out of the box. Now anything is possible with modification.

I wish I could confirm thatANY 06 klx300 aftermarket slip on will bolt up to the 06 klx250s if you use a klx300 head pipe.

 

I read somewhere that the KLX250 engine needs a certain amount of backpressure for the low end and the larger aftermarket head pipesdo away with some of the backpressure and low end but help alot on high end...dunno...that might have been on HMF's website [8D]

 

I wish someone could explain to me (in terms I can understand) the "some amount of backpressure is necessary" part about four stroke engines (if in fact that is true). Back in auto shop (the early '70s) I was taught that the purpose of "headers" was to eliminate back pressure. If we were striving to eliminate back pressure in an auto (four stroke), why would I want "some" in my motorcycle? I hope it's something to do with the 1 vs 8 cylinders. How do you measure "some" backpressure?

Mikem1965,

The aftermarket exhaust really wakes up the bike. They're not worth what they cost, but what can you do. I got a quote of just over $300 for a complete 3" dual exhaust for my pick-up, but the little can and headpipe for my KLX was nearly $400. Go figure. I have the Big Gun with the race core. It was supposed to come with the quiet core, but it didn't. I like the sound, and I can set off all the car alarms in the parking garage at work with only one quick rap of the throttle. I always leave work laughing...