I went to a KLX250 after riding my brother's 250. I was riding a 650, but big and top heavy. I like the lightness. The suspension is adjustable and also can be revalved and resprung to suit the rider, good stuff. There are known fixes for carb jetting and I do a cam chain tensioner to replace the failed ones, which is pretty common. There is a chance the tensioner may already be on a used bike. If the cam drive is noisy use it to cut down your purchase price, then replace the tensioner. That usually fixes that.

If not jetted they are miserable cold starting/running machines. When jetting is done with either Dyno Jet or Kiehin parts the bike becomes easy to start and quick to warm up, as well as picking up power. Handle bars are supposedly not a great bend, mine had Renthals when I got it. Hand guards would be nice for the North Woods there.

The bike has a lot of potential hop up stuff including the fact that the KLX300 top end is a bolt on and there are also some big bore kits out there. Actually there is a Chinese 300 kit for under $200 that does well. Pipes can be had, bigger flat slide carbs. Skid plates, carrier racks, etc. Oddly enough I have that stuff sitting in the garage waiting to be put on the bike, but it seems I just can't get to the job due to other tasks.

There is a lot of stuff and this is the best forum for the KLX250/300 out there. I have a couple documents in my signature, one has the link to D Pippin's very complete web site for the KLX. Take a look. The bike's been around long enough to have a lot of the tricks down pat and Pippin's done a lot of them and documented it.

 

"I went to a KLX250 after riding my brother's 250. I was riding a 650, but big and top heavy. I like the lightness. The suspension is adjustable and also can be revalved and resprung to suit the rider, good stuff. There are known fixes for carb jetting and I do a cam chain tensioner to replace the failed ones, which is pretty common. There is a chance the tensioner may already be on a used bike. If the cam drive is noisy use it to cut down your purchase price, then replace the tensioner. That usually fixes that.

If not jetted they are miserable cold starting/running machines. When jetting is done with either Dyno Jet or Kiehin parts the bike becomes easy to start and quick to warm up, as well as picking up power. Handle bars are supposedly not a great bend, mine had Renthals when I got it. Hand guards would be nice for the North Woods there.

The bike has a lot of potential hop up stuff including the fact that the KLX300 top end is a bolt on and there are also some big bore kits out there. Actually there is a Chinese 300 kit for under $200 that does well. Pipes can be had, bigger flat slide carbs. Skid plates, carrier racks, etc. Oddly enough I have that stuff sitting in the garage waiting to be put on the bike, but it seems I just can't get to the job due to other tasks.

There is a lot of stuff and this is the best forum for the KLX250/300 out there. I have a couple documents in my signature, one has the link to D Pippin's very complete web site for the KLX. Take a look. The bike's been around long enough to have a lot of the tricks down pat and Pippin's done a lot of them and documented it."

I agree, the bike feels very light. Seems like it has a low center of gravity.

Is the cam chain tensioner hard to replace? Definitely don't want to buy a bike that has problems already to begin with.

My buddy rejetted his ATV and it runs/starts a lot better now compared to stock. I watched some Youtube videos and read some threads on it, doesn't seem too difficult to do. I've worked a lot on older cars over the years so I have some mechanical inclination. I'm very familiar with how Edelbrock carburetors work on old cars, able to change out jets and other stuff in those, so I'm assuming that would carry over to some extent. I also tore down my old Suzuki PE250 with the help of my buddy years ago, so I have some experience.

Sounds like it's a pretty solid bike.

My Dad has a 1996 Honda XR250L that is in pretty good shape, low miles, just needs a couple things (oil leak at top of the head and carb needs to be gone through and freshened up). I could possibly just buy that and get a bike that I know the history behind. But it's quite a bit older and is kick start only. I've been riding my Dad's 2016 Yamaha XT250 and it's really nice with fuel injection and electric start. Just push a button to fire it up, hard to beat that. I really like the look and feel of the KLX though, pretty neat looking bike.

I'll read up on that thread you mentioned too, thanks!

 

Nah, tensioner is easy, about 1/2 hour taking your time. The jetting for me was pretty cut and dried. It needed to be done because everything carbureted over the past decade or so has been lean due to EPA/DOT regs. I like the bike because it is based on the KLX300R which was rock solid. That's pretty much where the Keihin jetting comes from. Back around 06-07 guys realized the need to jet and looked to the 300. It works pretty good. From there nothing really to be worried about.

I have a tough time doing the hop up stuff I got, don't feel like taking the bike apart, it runs fine... but I know the carb and big bore will give it some serious punch.

 

 

Cool. I'll have to keep that in mind if I end up getting a bike in the spring.

Yep all the newer stuff nowadays is lean. I have some Stihl equipment and the newer stuff definitely runs different than the older stuff.

Sounds like the way to go for some easy power is to jet the carb, open up the airbox, slip on a better free flowing muffler, and swap to a 13T front sprocket. None of that stuff would be too expensive or involved and sounds like it really wakes the bike up over stock.

The 351 big bore kit sounds pretty sweet too, but obviously much more involved. It'd be easy to do that if your engine needed a rebuild, but if it's already running great with no problems, I'd have a hard time tearing it down to do that.

My folks and one uncle are swaying me towards buying a new one. The new ones have fuel injection. From what I've read Power Commander just came out with some tuning abilities, but not sure if they have all the mapping stuff sorted out yet. I'm familiar with tuning stuff from my 2015 Challenger Scat Pack, had to swap PCM's and use a tuner for that, alter the ignition timing, installed a wideband and dialed in the fuel better at full throttle, really woke the car up and picked up at the dragstrip. I'm assuming it's something similar with tuning these modern bikes as well. I sat on a new one at the dealer and it sure felt nice. Tempting.

Used ones are much cheaper though. I've seen many nice used bikes with under 5K miles going for $2500 or so give or take a few hundred. Brand new they are about $5K. Could save a lot of money and spend some dough on mods on a used bike and still be ahead. But then again having a brand new bike sure would be sweet. My Dad bought his Yamaha new and he's been really happy with it. Starts up easy all the time, looks great, rides great, etc. Could argue either way really.

 

if you can afford a new one, that's always good.

When you add 50cc to a 250 you just increased it 20% displacement and as they say - "there is no replacement for displacement". Bigger displacement means more power, period. A 351 would be nice. Almost 30% bigger. I used to be anti big bore until I actually did it with my 650, going 2mm bigger to make it a 678cc. Much stronger with only that small increase and it wasn't a higher compression piston either. Pure displacement increase.

The KLX has the possibility to have it done and pick up good power across the rpm.

 

Well, it's affordable, just not sure it makes sense given the limited time I have to ride. But it would be nice to have a brand new bike, that's for sure!

When guys talk about jumping up to a 300, 331, or 351cc big bore, what all is involved with this realistically? That's likely beyond my ability to do on my own. Are people doing these all on their own in their garage with basic tools, or are they taking it to shops or dealers and having it done? I'm sure I could yank the motor out of the frame, I did that on my old Suzuki, but disassembling the rotating assembly and all that, not sure I'd want to take that on. Is this a $1,000 or less mod or are we talking much more?

I looked up the specs of my old Suzuki PE250. Says it made around 28hp around 8000RPM and 20ft/lbs at 6500RPM's and weighed 245lbs dry, so maybe 260lbs wet or so? The KLX is around 18-20hp, and for some reason I cannot find the torque specs. I'd like to know how much torque and at what RPM level peak torque is at. It's also 40lbs heavier than my old Suzuki, likely from the starter, fuel injection stuff, all stuff that makes the bike that much nicer really.

I'm assuming the KLX is faster than the Yamaha XT250, but by how much? I rode my Dad's last weekend and it went along fine, it's not fast by any means, but I never felt like it was underpowered for what we were doing.

I could see rejetting the carb, airbox mod, muffler, and 13T front sprocket as basic easy mods to do to wake it up a little. Kind of like throwing a 4 barrel carb, aluminum dual plane intake, headers, and 3.73 posi on an old small block Chevy car. It's not going to be a rocket, but it'll definitely wake up over a stock setup and feel noticeable.

 

My other question is, how great or not great is the Suzuki DRZ400? I joined up on Thumpertalk recently and everyone over there is saying I should get a DRZ400. But when I sat on one at the dealer, the thing felt so big and heavy, and top heavy at that. Sure didn't feel like a bike I would want to take back in the trails even with knobbies. But a ton of people do it and seem to love it.

The KLX just felt right when I sat on it. It wasn't too high or low, I could flat foot it sitting on it, the bars felt right, all the controls felt good, the color looks great, and I know those single 250cc engines are bulletproof.

Just curious if anyone has had a DRZ400 and what they thought of it? I've had some recommendations of the Yamaha WR250R, but those are much more expensive, and frankly I'm not a big fan of how they look either.

 

I'm a big KLX fan, but before I spent the money on a brand new one I would search for a clean KTM for the same money.