They are rated exactly the same here in Japan (28PS at countershaft). I think the method of measurement is different in the case of the two manuals. KLX is probably a rear wheel measurement.

Yeah, I see your point on temp vs HP. It would just be nice to have some empirical data to back-upsuch a large swing. I've basically recoverd all of the drive train loss by way of colder temps...wierd, huh? [8D]

Time to start chucking dry ice into the airbox

 

Well, I think you should trust it, Dean, unless proven otherwise. I'll trust a calibrated dyno machine any day over guestimates and hand waving. But I do think something is up - maybe not the machine, but there's got to be an explanation. A16Tony and Scat both dyno'd their bikes back to back and got within 0.5 HP of each other and were seeing around 22 or so, if I recall, and theirs had the airbox/carb/pipe mods. Mine was just a hair under 27 HP and that was with airbox/carb/pipe/big bore mods. So if we trust that data, and based on what we know about the stock 17 or 18 HP, the airbox/carb/pipe mods give about 4 or 5 HP and the big bore is worth about another 5.

But you are seeing 10 HP from just the airbox/carb/pipe mod. Unless there is something real special about your exhaust, other than it's the coolest exhaust I've ever seen, there has to be an explanation. I'll freely admit I'm no expert but I'd be surprised if the cold air would account for the 5 HP and like someone else said, I thought the dyno was supposed to factor that in? Again, I'm far from an expert, so maybe that is in fact the explanation, maybe someone with some expertise in this area can chime in.

Anyway, I tend to believe the dyno, no reason not to. But I would look for an explanation as to why yours is so much higher. But I wouldn't discount the results, they are what they are. Just consider it a pleasant surprise.

Also, when I got my 27 HP run, I had a Kenda K761 rear tire. It is claimed a 50/50 tire, but it is pretty smooth so I don't think your rear street tire can explain it all. My tire was brand new and they say they are slicker when new and you need about 100 miles on them before they bite good, but I don't think that would account for it either. I do think the rear tire can make a big difference, though. I'm just saying that I had a decent rear tire on my 27 HP run, so that doesn't account for the difference.

Congrats on the dyno results - that's some good stuff right there!

 

I'm confused, the manual for my bike (klx250-d1, d2) claims 23.5KW (32 ps) @ 8500rpm, but you guys state only 14hp from a stock bike am i missing the point here or are UK spec bikes completely different from US specs as the manual states 18.4KW (25 ps) @ 8000rpm for the US model.

Simon L

 

TheUS specsappear to be measured at the rear wheel wheras the UK is probably using a countershaft measurement. Just a guess.

 

I'm with you on all of that, and I'll take it a step further. I remember reading a dyno run on D-tracker that had an aftermarket exhaust similar to mine, pumper carb, 315cc large bore kit and aftermarket cams installed that netted the same HP as mine. Something is not adding up. I think I'm at the stage where I'll just wait until things warm-up (for my own comfort if nothing else) and go get a 'second opinion.'

 

We all know that every Dyno is going to give you a different reading. But you have some good numbers showing at that ambient temp with your setup. I agree, take another run when the ambient temps get warmer on the same Dyno to meet your curiousity. Nice looking ride ya got there tremor38