KTM horsepower claims

Buzz Bomb

Does KTM take the public for idiots? I was reading the Dirt Rider for this month, and KTM claims that it's 2002 125SX has 3 more HP for a claimed 41HP!! I mean get real, some 250s don't even make that much. I know the KTM is a fast bike, but comon, don't push your luck.

dirt bike dave

Sponsoring Member
This is along the lines of the recent thread about claimed weights. As Rich pointed out in that thread, the manufacturers usually have a way to defend their numbers.

Here's a few ways KTM can get such a high number:

1) Use crankshaft HP, not rear wheel hp
2) Run it in a pressurized dyno room with extra oxygen pumped in and don't correct for standard atmospheric conditions.
3) Allow a wide range of squish band height and combustion chamber volume on the spec sheet, and make sure that the engine you dyno is at the extreme end of the range for max HP.
4) Special fuel

With the exception of professional riders and tuners, people should stop paying attention to peak HP figures, IMO.



I read the same article, and I think you read it wrong. First of all, it said in the article that they measured it from the rear wheel on a dyno. And secondly, they said that it was a "works" Ktm 125sx, which means it had thousands of dollars put into it to make it have more power...


Apprentice Goon
Dind't they list the '01 at 34.2 hp?


Mod Ban
All the manufacturers exagerate their horsepower numbers. These numbers are arrived at by using a hand-picked, perfectly assembled engine, running on a dyno in a perfect environment, and they report crankshaft numbers, not rear-wheel numbers. Driveline losses can easily exceed 20%. If I remember right, Honda claimed 55 hp for the '01 CR 250. Does anyone here think that is a realistic figure? It's all marketing strategy.


Crazy Russian

Not that I believe anything written in a magazine or claimed horsepower figures, but quoting this months Dirt Rider article, regarding the KTM125, page 48 -

"We hear reports that the works KTM's pump out 41 horsepower at the rear wheel on the dyno. KTM's 2000 model 250SX made 37 horsepower on the same type of dyno. The motor remains the magic in the 125SX package."

It sounds like they're saying that the works 125SX puts out more peak power than the production 2000 250SX.

There's nothing stopping anyone from embellishing the numbers or creating a little hype. :confused:

David Trustrum

Kawasaki used to (still?) measure their roadbike (& presumably dirtbikes) hp by reading rear wheel hp then removing the top end & rod driving the engine up to speed with an electric motor to calculate loses, add that onto the original run & claim that as crank hp.

The logical progression is to measure fuel consumption, assume no losses & claim the calorific value of this. 100 hp 125 no wurries!

Mid 30s for a 125 is pretty good. But what is the potential? Well RS125 Road racers were originally derived from CRs. The early ones wheezed out 30hp 10ish yrs ago. Now they are seeing mid 40s on proper gas & setup & some top level tuners are now expecting to graze 50 but these are like works level.

‘course before you salivate too much the development paths separated a while back but more importantly one of these engines in the dirt would be unrideable, even for factory riders unless you removed the dirt, the corners, the need for acceleration. . .

Buzz Bomb

Re: ?

Originally posted by holeshot
"We hear reports that the works KTM's pump out 41 horsepower at the rear wheel on the dyno. KTM's 2000 model 250SX made 37 horsepower on the same type of dyno. The motor remains the magic in the 125SX package."

It may have been a works 125 in 2001, but they also said the cylinder on the 2002 was an exact copy of Langston's race bike, so technically it is the the same bike.


In the newest issue of dirtrider KTM claims a 3hp increase over last year. It said that their works bike put out about 41hp. They didnt claim 41hp for the '02 125sx
in the article Dirt RIder claimed that the '02 and Grant's race bike have the same cylinder, but call me crazy, i think there might be a little difference between Langston's full factory ride and the '02 sitting in my local KTM dealership


Lifetime Sponsor
Sorry to spoil KTMs fantasy but from 99-01 the 125sx has put out roughly 32-33hp.it depends on which bike on which day.Each year the peak Hp has been the same but the engine has got easier to ride on the later models.A well sorted 01 with mods puts out 35hp.I dont beleive any manufacturer when they claim 3hp more than last year.3hp on a 125 is a huge amount that takes years to acheive.Even if we had langstons barrel it wouldnt be setup the same a his bike.The crankcases/transfers arnt matched on a production engine.The squish clearnances will be bigger due to pump fuel.He runs a v force on his as well as a DOMA pipe etc. These claims of 41 hp are put about to send the rivals to the dyno room to ruin there engines making them more peaky.Ive seen dynos of World GP bikes and they arnt 41hp-not even close. Factory tuners look for a very straight line on the dyno-peak numbers are a waste of time.MX is about torque not HP.
Must read article more carfully

The article said the factory race KTM 125's are dyno'd at 41 HP and that the new 2002 will have 3 more horsepower than the 2001 model. There is no mention of the 2001 models stock HP.


Lifetime Sponsor
KC i said i seroiusly doubt the 02 has 3hp more than the 01 stock or are you replying to a previous comment that wasnt mine?