KLX Mods, whats best

[jj white]

Hi guys. Recently got a 09 KLX. Need suggestions on the best sprocket, pipe and carb mods to increase dirt performance

[TNC]

Have you read all the threads on the upgrading of the KLX250 on this section of the site?  There are many, many sources here.  Marty has many posts on the subject himself.  I read just about everything contained in most of these posts, and they pretty much answered questions I had when I recently purchased a used '06 model.  Do you have some specifics about your KLX that you're dealing with?

[jj white]

Read some of the threads. What mods have you made to yours?

[TNC]

My '06 has the basic mods that most do...all airbox mods with screen removal...full Muzzy exhaust...rejet to fit mods.  These produce some worthwhile power gains and a broader powerband short of a big bore kit.  Mine also has a Vapor instrument panel, no turn signals, Renthal bar, Acerbis hand guards, etc.  I've also done a Nuetech tubeless system.  With the exception of the Vapor and tubeless, these are the most common types of mods that most do.  I'm going to modify the front and rear suspension a bit to fit my style of riding.

[jj white]

Hey guys. So far for the KLX 250S got bark busters, 13 tooth front sprocket, 80/20 knobbys.  FMF exhaust ordered. Havin fun. Like this lightweight little machine. Might make this my main off road machine and use the KLR for occasional offroad.
Oh!!!! This thing runs out of gas too fast.  I'm used to ridin the KLR which that never happens. Got to order a bigger gas tank.

[Green Machine]

That's a perfect combo 

[jj white]

Will the 3.7 gal. Acerbis tank fit my 09 KLX 250s? I had read on some other posts that it would on some a couple years older than mine. JJ

[TNC]

It fits but it takes a great deal of work to do so the last few times I've seen it done on '09 and later models.  If you check a poster's excellent post on this subject over on ADV by the name of NorCal...I believe that's the name...he did a great writeup with pics.

[TNC]

On the KLX mods in general, I've recently finished doing a Race Tech Gold Valve conversion on the fork and shock of my '06 KLX250.  This past weekend I finally got to ride the finished product at what is usually considered the toughest, roughest enduro course in the Texas state enduro circuit at Ross Creek...known as the "Concho Enduro".  This place has rocks, ledges, rocks, hills, rocks, canyons, and more rocks.  I had ridden my KLX out there back in December while returning from Big Bend NP, and it was fairly lacking in the suspension department.  This weekend the newly valved and shimmed KLX was downright amazing.  It tracked straight in rock, ruts, and ledges.  It was ultra stable in braking bumps, v-dips, and g-outs.  All compression spiking was gone, the travel seemed bottomless, and small bump compliance was butter.  To me it seems this particular bike should have no business performing this way in the suspension department.  I've ridden some of the other club member's bikes like Honda 450's and KTM 400/450's.  Those bikes had an obviously distinctive weight and power advantage, but I can honestly say that the suspension manners were no better than my modded KLX.  I truly believe that I'm not star-struck by my KLX by any means, but this mod was really remarkable.  I highly recommend it as an extremely worthwhile mod if you ride yours in any challenging terrain.  I did both the fork and shock myself, and it's the first time for me.  It wasn't rocket science, and the Race Tech one hour vid was an awesome tutorial.

[jj white]

It fits but it takes a great deal of work to do so the last few times I've seen it done on '09 and later models.  If you check a poster's excellent post on this subject over on ADV by the name of NorCal...I believe that's the name...he did a great writeup with pics.

      Thanks

[TNC]

I was off a bit on the name.  The ADV Thumper forum post on the Acerbis tank was by wishin4woods, and the post of the writeup and pics was by GSNorCal.

[anomad]

.....This weekend the newly valved and shimmed KLX was downright amazing.....
..........It wasn't rocket science, and the Race Tech one hour vid was an awesome tutorial.........

Good to know TNC. May I ask where you purchased your suspension goodies?

I'm still looking at some down time before the snow melts and things dry out. Maybe rebuilding my shock is a good project.

[TNC]

.....This weekend the newly valved and shimmed KLX was downright amazing.....
..........It wasn't rocket science, and the Race Tech one hour vid was an awesome tutorial.........

Good to know TNC. May I ask where you purchased your suspension goodies?

I'm still looking at some down time before the snow melts and things dry out. Maybe rebuilding my shock is a good project.

I got the stuff from Tucker/Rocky through the shop I used to work at.  I got the shock and fork Gold Valve kits for the 300 and used the recommendations from Race Tech for shim and external rebound and compression adjustments...except for the springs.  I may have gone with the fork spring recs at .44 versions, but I went with a 6.0 Eibach rear spring.  While I was in there, I installed a new seal head assembly, also from Tucker/Rocky.  The rear shock required almost no tech or really any special tools.  The fork required me to use the shop's bearing/seal driver for final assembly, and I made a damper rod 4-prong holder out of an old aluminum bicycle seatpost that was relatively easy and worked excellently.

Anomad, I kid you not...this was an utterly transforming mod.  They say you can't make a silk purse out of a sow's ears, but this has to be about as close as it gets.  You know, from looking at the Race Tech vids that came with both kits on general shock and fork rebuild and mod procedures, the shock and fork on the KLX isn't that antiquated, at least by design.  The shim and valving, however, are somewhat horrible.  This mod has delivered a whole new bike.  I'm heading back out this morning to spend the weekend out at our enduro course riding area.  The Nomad MTB has been collecting dust for 2-3 weeks now.

Seriously...if you have one of these bikes, tweaking the front and rear damping is so worth the money and effort.

[TNC]

And here's a shot of the finished shock shaft and new valving.

[anomad]

Sold. 

First things first though...I need to get this DRZ on the road!

[jj white]

It fits but it takes a great deal of work to do so the last few times I've seen it done on '09 and later models.  If you check a poster's excellent post on this subject over on ADV by the name of NorCal...I believe that's the name...he did a great writeup with pics.

Hey TNC. That acerbis tank did take me a little time to work it into place. Had to take about 1/8 in off of the rubber on top of the bike frame just to get it to squeeze into place. Also the choke button, had to take most of the plastic button off to be able to operate it. Don't need much choke though with the carb rejet. I think I need to put a crossover gas line on the tank from one side to the other to be able to use up all the fuel. Any suggestions on this.

[TNC]

If you're worried about the fuel in the lower wings, it ends up being close to .5 gal in there.  If you look at the main sump between the frame rails that contains the petcock, you can lean the bike over and get most of that fuel out of each wing.  I've done this, and it works fairly well.  You can use 3.3 gallons of fuel pretty well uninterrupted after the petcock has gone to reserve.  You've had plenty of warning up to that point.  When you have to go to the tilt-and-fill method I'm talking about, at least you still have that wing fuel which will get you another 25 miles at minimum.  That's not bad insurance for not paying attention.  If you're the kind to push that far past the petcock reserve, then you're also probably the kind of person to run out the wing fuel if you've plumbed a line for access to that fuel.  Granted, you can't ride any gnarly singletrack and bounce the bike around after doing the tilt-and-fill deal, but why would you.

All that said, I've seen some very decent plumbing efforts to access that wing fuel.  I'm happy with it just being there for the worst case scenario. 

[jj white]

If you're worried about the fuel in the lower wings, it ends up being close to .5 gal in there.  If you look at the main sump between the frame rails that contains the petcock, you can lean the bike over and get most of that fuel out of each wing.  I've done this, and it works fairly well.  You can use 3.3 gallons of fuel pretty well uninterrupted after the petcock has gone to reserve.  You've had plenty of warning up to that point.  When you have to go to the tilt-and-fill method I'm talking about, at least you still have that wing fuel which will get you another 25 miles at minimum.  That's not bad insurance for not paying attention.  If you're the kind to push that far past the petcock reserve, then you're also probably the kind of person to run out the wing fuel if you've plumbed a line for access to that fuel.  Granted, you can't ride any gnarly singletrack and bounce the bike around after doing the tilt-and-fill deal, but why would you.

All that said, I've seen some very decent plumbing efforts to access that wing fuel.  I'm happy with it just being there for the worst case scenario. 

Thanks TNC. What you suggest sounds like a good idea to have extra range and insurance.