Seen it stated as 23hp to 28hp for a stock bike. What's the truth?

 

Do a google if you want to see Cycle World's dyno numbers for the stock one. I forget exact numbers. I'm thinking high 18, maybe 18.7 hp.

 

...We measured 21 peak horsepower at 8100 rpm on the Cycle World dyno, ...


Riding Impression: 2009 Kawasaki KLX250SF: Kawasaki?s new supermoto-style KLX250SF defies the notion that an entry-level machine must be mundane.


Add exhaust, jets, and cheap mods and get more, on CW's dyno.

 

Don't know why, but the last 2014 Cycle World shoot out showed the S model around 18.5 hp.

The stupid part of their shoot out was their "excuses" for slamming the KLX - bad handlebar bend and mpg. Their mpg was 63 with the WR at 63, with the CRF at 67. I'm not losing too much sleep over 4 mpg, although it is a chunk.

I wonder how the jetted stock bike would compare. Too lean can be as bad as too rich when it comes to mpg from my experience. Plus the jetted KLX would stomp the CRF... well as much stomp as a 250 dual sport can do.

 

Just my opinion, for a one cylinder 4 stroke motor, the 250 can get from 0 to 60 like no ones business. From a stop light I've out run cars and other motorcycles that were triple the horsepower.

 

HMF used to have a thread on their website showing how to remove the carb. It was a good set of instructions. It included a dyno chart showing stock vs. piped and jetted. I copied the numbers off. You'll find my curve in this thread. About 18 hp stock.

https://www.kawasakiforums.com/forum...numbers-38674/

 

There is this one from Kustom Kraft showing 16.6hp and 11.69 trq.. I tend to believe that the bike Kustom Kraft used is really dead stock, before and after the 330 kit, because I'm making the same power with my modded stock bore as they are showing on their 330 big bore kit.. So that kit is likely on an otherwise dead stock bike - so the "before" was also likely dead stock.. Make sense?

None of the magazines will show complete dyno charts like the one below, and that makes me think bad thoughts about the truthfulness of the numbers.

As below - WinPeP 7 with SAE correction factor, smoothing factor of 5, and complete run details including the SAE correction - that's a chart you tend to trust..

I can't seem to get the image to post using my usual technique, so here is the inserted link..
KLX250_Dyno_chart_6_22_11.pdf

 

To your question . . . where have you seen it stated 23 to 28 hp stock?

 

Never say never...



Motorcycle USA also ran the torque chart too, in the gallery. Index down.

Key thing with any dyno work - has to be the same dyno to get realistic comparison. Best if same day too. Dynos are both electronic and mechanical. Variances in equipment and wear can cause differences from dyno to dyno as well as the manufacturer. That was something Cycle World and others used to mention, their readings were normally from the same source.

Dyno figures in one run on one set up are more reference than reality since weather can drain or add power. It's when there is real comparison, like I think you and I know Marcelino did. A base or benchmark for comparison after modification, using the same dyno under same conditions.

So suffice it to say the 2009 and up are around 18-20 hp depending on variables, the Honda is about the same, and the WR kicks both their butts! But then do some jetting and a bit, like you did, and the KLX kicks the Honda's butt and is closer to the WR. It ain't all bad having a carburetor when the bike can be rejetted for more power - is it?

 

Not sure what Kaw claimed on the 2006 and up, but I think the first ones in 1994-95 KLX250R, precursor to the KLX300R, were claimed at 28. That's a guess without looking it up.