After having ridden 3 different WRR's, I've come to the conclusion that we probably have a better off road powerband on our KLX. I finally got to ride a fully prepped WR250R on my recent 2 week Big Bend area camp and ride trip. I camped and rode for a couple of days with another Texas rider who had the best prepped WR250R I've gotten ride yet. It has a fuel programmer, airbox mods, and a full FMF exhaust. While it had a very strong mid-range to WOT response, it was nothing near the stump-pulling low end of my KLX. Now, I do have a 300 jug and a 36mm pumper carb on mine, I can recall the excellent low end that my bike had even when it had the CV carb, stock bore, full Muzzy exhaust, and all airbox mods. I've always been impressed by the strong low end out of a mildly modded KLX, especially compared to the relatively anemic response of a stock, carbureted KLX.

Regardless, I was a little disappointed in the low end grunt of all the WRR's I've ridden, and this one had all the necessary mods with the excepetion of a bigger bore. It had a really strong hit in the middle, but I would sorely miss the low end grunt of my KLX. I can get downright sloppy at times in gear selection in some pretty gnarly terrain on my KLX, and it is very forgiving. In a couple of scenarios on this trip, he had to keep his WRR wicked up while making some tough, loose, rocky climbs which resulted in the back end stepping out in some loose rock which brough him to a halt. The KLX just seems to tractor up the same terrain with the rear tire sticking like glue. It seems like a horsepower/torque balance that the KLX has that the WRR doesn't have in certain trail conditions. We didn't do any drag races or roll-ons, so I can't say how they would have compared in that scenario.

I've always put the WRR on relatively equal footing with the KLX, but I'm thinking now that I'd probably choose the WRX for the motard version but stay with the KLX for anything involving trail riding.

 

TNC, did the WR250R have the same gearing setup as your?

 

If I recall, the WR has a shorter stroke resulting in lower torque. That is also why they like to scream in the upper range.

 

Yes, good question. I failed to mention that he had exactly the same gearing which is why the low end response issue struck me as disappointing.

 

How would you think the big bore would compare?




The torque and most of the power still arrives in the mid range and like to be up top as TNC said. It makes you think that you could go even steeper with the gearing though, because the motor likes to be spun up so much.

 

Wow!...I'd read some of High Five's post on ADV about installing the 292 Athena piston but not all of it. RSM, that dyno chart you post there isn't clear, but I'd find it hard to believe that the OEM graph isn't exactly that...totally OEM...no pipe, no bigger bore, no mods. And then I'd suspect the 292 graph to be the 292 piston with mods. I can't believe just 43cc with all other mods on both bikes would produce that big a difference. The KLX 300 is the same 292 deal as the WR Athena setup. My bike had all the mods of full exhaust, airbox, and DJ carb mods before I did the 300 piston. It was a noticeable wakeup call for the 250 when those mods were done. Adding the 300 piston after that was another low end grunt improvement, but not overwhelming. Another kick of improved response and even WOT occurred with the 36mm pumper.

So yeah...my setup to my friend's WR isn't an exact apples-to-apples comparison.

 

No I'm not saying it wasn't apples to apples, a wr250 with all the uncorking mods will always be faster than a klx250 with a 300 jug kit just because it is a top end screamer and has more power stock for stock to begin with. I just find it interesting that after the big bore kit on the wr, based on the dyno at least, it looks like the klx will still have more usable low end torque, even more so with the 351.

The wr290r with 31hp at the upper end reminds me more of a mx type of power band, probable better for going to the track on the weekends and hitting some big whoops vs tractoring up a steep rocky incline...IMO

Here's a clip from a topic I just found on TP 290cc Athena big bore kit hits 31 hp! - Yamaha Dual-Sport - ThumperTalk

"Out of curiousity, I compared the numbers at several points (my son isn't around to make the jpeg for me). It was tuned on a Dynojet. Obviously numbers vary between dyno's. However, he said that the prior two WRX's had put down just under and just over 32rwhp (but, he said mine tuned out/ran better relative to AF...).

Mine at 5500 makes 15 rwhp
at 8500 makes 30 rwhp
at 9000 makes 31.17 rwhp
at 9500 makes 30 rwhp
and holds 30+ rwhp until the rev limiter

ranges from 16 fp of torque to 18.68 between 5500 and 9200

The dyno of the big bore kit bike (I was guesstimating looking at the picture)

at 5500 makes 20 rwhp
at 8200 makes 30 rwhp
at 9000 makes 31+ rwhp (couldn't see the exact number)
at 9500 makes 29 rwhp
and hold 28 ish rwhp until just before the rev limiter and then drops

ranges from 17-19 fp of torque between 5500 and 9200."

 

The only thing about the WR that makes me want one is the stator output. I've read stuff on ADV where guys just plug in whatever they need, GPS, USB phone charger, heated gear, etc. That would be nice.
I like the tractor factor of the KLX, it has pulled me out of the **** a few times!

 

The WR likes to be ridden in the 6-9k rpm range where I think the KLX likes from 4-7k rpm. At least that's what my experience is. Makes for some tricky technical riding even when geared down compared to the KLX.

But, I'm a noob so maybe more experienced people like it.

 

On the electrical power output, I noticed an interesting thing concerning my buddy's WR and his Shorai super light weight battery. He had a reasonably new Shorai battery in the bike. We stopped at a big overlook out in the desert for a view and a snack. He accidently left his key on. The headlight doesn't work on this bike without the motor running. About 20 minutes later we prepared to ride on, but his bike wouldn't start. I pushed him down a small hill, and it started up. I don't know exactly why the battery was so low from this stop, but I wonder about those super light weight batteries. He didn't have any other issues at any other stops on the other days, so I don't think the battery was on its death bed or such.