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My bike's horsepower?!?

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Well, I wanted to figure out how much horsepower my bike had, and since I don't have a dyno handy, I looked in the manual and stock it makes 40.1 kW. Well, to get horsepower from kW, google says you multiply by 1.3410229. So if this is true, then my 1999 KX250 makes a mean 53.774985809 ponies stock :applause: :applause: ! Add about 4 for the Pro Circuit pipe/silencer, and there you have it. My bike makes almost 58 horsepower!

This doesn't seem very realistic. Is it?

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Well, I wanted to figure out how much horsepower my bike had, and since I don't have a dyno handy, I looked in the manual and stock it makes 40.1 kW. Well, to get horsepower from kW, google says you multiply by 1.3410229. So if this is true, then my 1999 KX250 makes a mean 53.774985809 ponies stock :applause: :applause: ! Add about 4 for the Pro Circuit pipe/silencer, and there you have it. My bike makes almost 58 horsepower!

This doesn't seem very realistic. Is it?

that is way out of proportion. google is never wrong, so its probably the manual. manual's tend to exaggerate to get you to buy the bike( not to mention some exaggeration on maintenance :lol: ).

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Crank horsepower and rear wheel horsepower are totally different things. Driveline lash takes a healthy percentage off the higher (crank) figure.

A perfectly tuned and jetted 250cc two stroke motor can easily achieve 50 HP at the crank.

putting that power out to the rear wheel is another story all together.

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Yeah the manual of my '00 KX125 said that it made 40hp stock. BS. It might have made 35 (I had a pipe on it). Chances are that you have somewhere in the 46-48 range if that much. 45 would be very believeable though.

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There's two things wrong that I see. It isn't the conversion, either, because that is, in fact, the right formula.

First, it's crank horsepower. Knock about 20% off that for losses in the transmission, etc., getting to the ground, and that leaves 43. Probably about right.

Second, I don't care what they told you, you didn't get 4 hp from your pipe. 2, maybe if the PC is real good, and the stocker totally sucked.

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No one told me 4 horse for the pipe, it was a rough guess that I made. 43 seems a little more believeable than 58 now.

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I'm not sure about the 2 smokes, but when I got my PC pipe on my bike and had it dyno tested at Langston it made a 4hp gain over the stock pipe.

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It seems to me that the purpose of putting a pipe on a two-stroke is more to move the powerband to where you need it in the RPM range, rather than gain horsepower.

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Yes, it is. 46-47 at the rear wheel is about right for a 250. A pipe will give you 1hp if you are lucky.

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I've seen some very impressive gains from a both PC and Bills pipes before on 2 strokes. We never put them on a dyno, but they definitely pulled MUCH harder. Seat of the pants I would have said 2-3 HP. It was definitely way more than the supposedly HUGE gains I've got from running VP U-4 in my 4strokes. I agree with NOMADAK's post above, I see that he's also old enough that he's probably spent a lot of riding time on 2 strokes like me also....

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my 2000 yz250 all stock except wisco piston and carbon fiber reeds made 43.5 rwhp at 9500 rpm......my boys 06 rm250 made 48 with a v3 reed system and a pc pipe....

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Ive heard its very common for a 250 in good shape to be putting out around 50hp or better at the crank, hell the new 450's are almost 60! 125's are usually in the mid 30's, 80-85's are usually in the 20's

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According to Dirt Bike Mag., the 2000 kx250 makes 45.5 horsepower at the wheel. 99 were similiar to 00 so I guess stock it would be around that.

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