The Complete KLX250/KLX300 Long Term Review Thread

Yeah and I have the KLX300 pipe and muffler on mine, and the sound is not at all nice. The actual stock pipe is very quiet and has a simple, if sewing-machiney sound. This thing, especially with the 351, and a quiet insert, just sounds bad. It sounds like the bike is congested too, like it needs more flow. But if I pull the quiet tip it'll be WAY too loud. I'm starting to think a Ninja pipe may be answer. Or just pony up for one of the "quiet" series aftermarket pipes, which will be louder, but at least sound better.

Rob

....ordered fmf header with power bomb & q4 muffler.
hopefully give my opinion on performance gain by the end of the week

Looking to buy a service manual for my 2006 KLX 250s. What manual would you recommend? And where to get it?

I'm looking for an official KLX250S thread that is the main thread where owners of the bike exchange info. Does one exist? I did a search and couldn't find anything.

This is it. The "other" KLX250S thread isn't used nearly as often, and we've all been wishing for years that the mods would close it.

Rob

If you're asking about a thread here on ADV, then this it it. However, some additional, very detailed, and even fun stuff that is dedicated to the KLX250 is over here.

http://www.kawasakiforums.com/forum/klx-250s-71/

Excellent, thank you!!

"The other thread" was someone's well intentioned attempt to keep the '06 - '07 info separate from the '09 and up info. If people don't mention which year their bike is, it can cause some confusion due to differences. And it's probably too late for a merge as that, at this point, would cause more confusion. To further confuse things is that North American KLXs are still carbed and the rest(?) of the world gets FI on their KLXs.

Has anyone tried both moving only the exhaust timing (post 428) and moving both intake and exhaust as in Marcelino's first post?

Does either procedure work better? Does one gain more by doing both vs only the exhaust?

As I read it, the ACR doesn't have to be messed with if only the exhaust timing is moved?

Thanks

No, the ACR is on the exhaust cam, so if you change it, you will have to change the ACR.

As I understand it, you have to do both to have any improvement.

Rob

Tomorrow I'm picking up a green 2009 with just under 1,800 miles for $2,500 bone stock. Couldn't pass it up.

Probably first thing I'll do is get some real knobbies on it. I like the 90/90x21 Pirelli MT21 Dual Sport Rallycross front and a 120/90x18 Dunlop D606 Dual Sport Tire rear tire. Used on both my XR250R and XR650L but I got to a 130 on the L.

I need to decide on what to do with the rear tail light. One superman into the sky coming out of a steep hill and all the junk is going to go crash, bang, smash 'em up with no putting it back together again.

I'm thinking maybe the Acerbis universal tail light.

Thoughts?

my 09klx has all the mods to the cv carb & the big snorkel in the airbox.
today she got the fmf powerbomb head pipe & the Q4 muffler.

It just became what it should have been all along.

It has transformed to the point its not recognizable as the same bike.
its also quieter than any of the euro bikes ive ever had with stock exhaust.

FMF POWERBOMB & Q4MUFFLER WORTH EVERY PENNY

Thoughts? I'm thinking "Superman into the sky? What bike is he riding? This is the KLX250 thread!".

That was just mean...but funny...and true...

He asked for thoughts.
I didn't intend any mean.

Do you have any pictures of the new head pipe and muffler? I have big gun EVO x exhaust on my 94 klr 250 and its loud, now I'm looking for something a bit quieter for my 06 klx250. Any video clips of it running?

Yeah, that's my one concern. The bike is more street than dirt. Love my XR250R but isn't great on the street and no magic button.

I don't know...I think you'll find there's a good deal of off road potential in the KLX. The suspension can be tweaked to a high level of performance, and the engine has a lot of options that really liven it up without much effect on durability and reliability. I had 4 XR250's from '84 until '90. I like my 300 jugged '06 KLX better than any of them. Race Tech revalving in the fork and shock, aftermarket pipe, 36mm pumper carb, and all airbox mods...damn near a real dirt bike with very good road manners...and only marginally heavier. It'll never be a KTM or such, but it's a darn good DS bike.

With the 351 and pumper carb on, for about 8 months now, the engine starts "coughing out" at around 8k rpm. Engine is smooth and responsive from down low up to 8k, and in the beginning with the big bore I was happy with that. But I'm reading that others with the 351 have the same RPM range as before... I did a few experiments and if I roll on the throttle slowly and gradually the bike eventually gets up to 10k-10,500 ... But if I accelerate hard and pin it, like I think most would do, it starts coughing .. Or skipping .. Not sure how else to describe at 8k ... Usually I back off and just switch gears at that point, the 351 gives you lots of leeway with gear selection because of available power .. But a couple times I kept the throttle pinned past 8k and the first couple "skips/coughs" and at 9k it started bucking pretty hard, it was very hard to control with loss of power and then it surging full on again-and off/on again at speed- Second run with same result was enough to convince me it wasn't going to resolve itself.
What the heck is going on? I've had three tune ups with valve checks over life of bike (800 miles, 4,800, and just a few months ago at 8,800) Always been told everything looked okay, valve clearances within range and reset to orig specs. It starts easy, runs well down low, but why is the high end not available, and what's causing that scary reaction at 8-9k under hard throttle - but not under slow acceleration? Beyond oil changes and a few basic tasks, I'm out of my pay grade and could use some advice...

Just hearing your symptoms, it sounds like a jetting or accelerator pump timing issue. Do you have a 34 or 36 pumper?