KLX250s Bottom end mods?
 

Hey guys, good news, decided on going ahead and buying the klx250s

Well, seeing as the dealership isnt open at 10 at night, i figured lets browse parts for it before i even have it!

Well, i plan on running a new pipe on it- I love the two brothers M-7 Sound and it looks amazing, whats the best header-pipe for it? (FMF Megabomb seems good, but i dont know how it would work well with the M-7)

Or what is the best pipe for the bike? (I want tons of lower and mid end)

Ofcourse I have read everywhere the bike runs lean and could use re-jetting.. The best kit? (id be getting this first since a 700 dollar system doesnt come after a new 5k bike)

What else helps this bike on the trails? (It will be mostly ridden on trails, with the occasional drag race on the road against my friends yz125,cr125, and kx250f)

The only external mod i want is some pro-taper contour bars with some bark busters


Over the winter i would like to bore it up to a 351, but as of now, that just doesnt look like something id like to do with my free-time (I am only 15 and would need alot of help from my neighbor who is a mechanic on motorcycles)

Thanks for all the help guys!

By "bottom end mods" do you mean lower end, simpler, less expensive mods? I thought you might be talking about the crank, rod, etc...like stroking the motor or such.

Anyway, the first thing to realize is that if your friends' KX and the two 125's are running properly, you will not beat them in a drag race without many engine mods, and I don't think you'd ever outrun the KX. Even 2-stroke 125's are mean little motor scooters in race form, and they don't weight anything.

OK, back to reality. When you ask "what else helps this bike on the trails?", the answer is simple...suspension. The rejet with Dynojet kit, simple airbox mods, and at least a muffler swap are almost a requirement IMO. The bike is so anemic in all of its emission required glory, that I wouldn't even own this bike if I had to leave it stock. After the rejet and muffler, the suspension actually allows you to ride this bike somewhat like a real race bike, albeit a heavy one. If you're going to ride real trails and not just dirt roads, you'll be sorry if you try to push the bike hard in any really rough off road conditions. This isn't cheap, but revalving both the fork and shock and getting the proper springs is the only thing that will really allow you to stay close to your friends...at least if they can ride worth a darn. A 50 horsepower KLX would still suck...and actually maybe even worse...if you tried to ride really rough trail and terrain with the stock suspension.

I do like your change of handlebar and barkbuster installation plan. Most folks who are going to really ride off road find these two items almost a requirement.

One other suggestion on your pipe selection. I'd recommend a complete head pipe and muffler from the same manufacturer that was designed and intended to be matched together. It's not that mix-and-match setups can't work, it's just that you're better guaranteed of getting the best results with a matched set IMO. The matched head pipe and muffler may also be a better foundation for the imminent 351 to come later.

If you want to haul your ash, it would be a lot easier getting a KTM or Huskaberg or at least a Kawa 450. Right out of the box, pretty potent machines. Why are you trying to make a KLX a race bike? My opinion is your way over your head & you may want to rethink your priorities or solutions.

351 or a different bike.

Buddy,

After reading your other post I was tempted to reply, but the other forum members covered all the bases. I say just get a used 125 moto bike, you will have more fun and spend less money than trying to make a KLX keep up with your friends bikes. I just picked up a modded 01 CR125 and it is a hoot. Like a mountain bike with a rocket strapped on compared to my 331 KLX or my KDX for that matter.

With all the mods you want and the performance you hope, you will be spending close too what ktm 450exc costs. Plus it has sweet suspension. As I said before, it's a race bike in a dual sport clothing.
my bet is you'll have a buyers remorse big time with all your expectation of the klx which it just
Is not.

How much do you weigh? I'm about 140lbs, my bike has 14t 49t, fmfq4, snorkle out, dynojet 2, trackmaster 2 tires. For my size and weight, it has sufficient torque but if you are heavier, you'll be wanting more. bikes a heavyweight if you drop it. But on the trails, I can keep up with my friends orange/ red/ blue bikes. I said keep up not beat them. Their bikes are just faster off the line.

Again thanks for all the info

I didn't say I'd beat them in a drag race, just that I'd be racing them.

I weigh 115 pounds and im 5'8 .

A 10k ktm just isnt goin to happen. I've been saving up for a year and have 2k, ill never get there.

And the used 125s in my area are just junk, not to mention I hate how loud a 2 stroke is

I have been debating a kx250f or a yz250f, but I want the street legal abilities that the klx, I've been riding since 5 (a pw50) and I'm not one of those riders who is reckless and flying around the forest..

I understand this bike is nothin compared to race bikes, but I don't track ride or even jump, just simple trails and fields?

Thanks for everything, I guess we will see once I start riding.

It's sad to see someone get buyer's remorse. Can you find a decent used KLX and try it out for less $$? If you don't like it, you'll be less in the hole than buying a brand new one. If you do like it but want a new one, sell it and move up. Just my 2 cents.

115lbs? simple trail rides? Then klx iss more than enough.after the mods were done on my bike, it's like having a new bike again. It's not any lighter but definitely it's got more oommmph now. Should have been like this from factory.