After lots of research I have my heart set on a new KLX250s. Ive been reading these forums for a few days and have a good idea of what mods I will be doing once I purchase one.

When you change the gear ratio (t13 sprocket) How is the speedometer re calibrated? does it read off the front tire or through the gear box?

Will I be able to handle highway traffic? Would it be best to avoid interstate driving and take alternate routs?

Is a full exhaust system worth the money? I understand its a 250cc bike and wont have 600cc power but want to get as much potential HP as I can out of it.

I did own an XR250 in the past. How does this bike (stock) compare to the power of my old 89 XR250?

Thanks for any info. Hopefully I will be able to purchase one an a couple of months.

 

Welcome, and good choice.

It's off the front wheel, so the 13T will have no effect.

I'm inclined to say you'll have no problem, but it does also depend on what sort of speeds you're needing to achieve, and for what sort of time. At 90-100km/h (56-62mph) I did a 25 minute stretch of freeway this weekend without any problem. Revs were pretty high (can't remember exactly, but thinking it was the 7000rpm range), but she had plenty to go still. Just wouldn't like to hold it open for much more than an hour though - just to preotect the engine.

In a word: POOR. The stock KLX250 is very underpowered compare to the old XR250 I used to ride. I actually had a bit of buyers remorse after I rode my bike home as she was so gutsless. This was also coz she was new off the showroom floor and needed to loosen up a bit. And loosen up she has, and hopefully she will do some more. Even now, I would say she is slightly underpowered compared to my old XR, but it has been 7 years odd since I rode the XR (and I am about 30kg's heavier now), so I could be wrong.

 

Thanks for the info Arctra

Have you done any modifications to your bike?

 

On the XR250 comparison, I had an '84, '86, '88, and '90 model. I raced enduros in those days, and while I should have have been using a bonafide 2-stroke race bike, I have always had a love for 4-strokes, and those Hondas also made very user-friendly trail bikes. I always had an aftermarket can on my XR's. I used a K&N filter in all of them and had them jetted just right. My '06 KLX250 with a full Muzzy exhaust, opened airbox, and Dynojet kit is the equal of any of my XR's in power. After putting a 300 cylinder on my KLX, it's noticeably beyond my XR's...as it should be. My KLX had 11,000 miles on it when I installed the 300 cylinder, and the piston, rings, and bore were in excellent condition with tested compression at the factory max. The XR250 needed a new piston and bore in less mileage than that. The watercooling is a plus.

If you're a bit serious about your dirt performance, the KLX's suspension has awesome potential with a revalve.

 

Where is a good place to purchase aftermarket performance parts for a klx in the US? Do you have to mostly shop around or is there an exclusive site you would recommend.

 

I get most of my stuff from Tucker-Rocky, but that's due to the deal I get through the shop I used to work at. Probably many of the inmates here can suggest some better price internet sources.

 

I have owned several XR and an XL 200cc bikes before the XR400 that I rode and raced (enduros/desert) the last 8 years. The stock KLX250 isn't that anemic to me though my weight of 160 might have something to do with that.

The XR250/400 RFVC engine is a fine motor but nowhere near as advanced as the KLX. I would expect that the KLX makes much more power than the XR250 OEM vs. OEM.

Then there's that wonderful estart button.

 

Arctra pretty much said it well. Only thoughts I would add to his comments are that for interstate riding, I certainly wouldn't say to avoid it altogether, but you may wish to consider getting the seat modded for comfort if you're doing it with any regularity.
Definitely dont judge it's power stock till it's broken in. I bought my bike used with 600 miles and it only just now 'woke up' around 900 miles and there's a distinct difference in it's performance.

 

Um, just read my posts signature. Short answer - yes, I have openned up the pipe and airbox and rejetted it.

The XR was fairly stock.

 

Some of the suppliers on here are willing to throw you a deal if you're a forum member, for example Utah Sports Supplies a great solid skid plate at a great savings. Additionally the vendors in the vendor list help support the site, which you can see is worth it's weight in gold for info and tips and is worth supporting vicariously through vendors. So I'd say look through the forums and the vendor directory at the top of the page after you've read the "mod day" thread. That will update you on lots of the free and innexpensive mod's you can do. After that, you can find a thread with just about every modification you'd want to consider. There are a lot of manufacturers that make a little of this, or a little of that that fit the KLX. Bill Blue's bike restoration business makes a healthy dose of purpose built performance mod's for the KLX inlcuding several direct swap displacement upgrades up to 351 cc's and a pumper carb to match, as well as stainless break lines, etc. Just depends what mod's you're looking for.