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ktm150sx vs tm 125

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what makes a tm better when we drag raced his bike pulled away breifley and then i caught up pulled for a brief moment and then he passed me why? i have v force reads and its a 150 what makes his bike better? he has mitchelens and i have stock but i studied the two and they are very close so why is his bike faster then mine?

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Because TM's are very strong fast bikes. I used to pass 250s with my TM125. Chances are that the TM is only stronger for the last 500 rpm, but that is what counts if you can keep it there.

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Because TM's are very strong fast bikes. I used to pass 250s with my TM125. Chances are that the TM is only stronger for the last 500 rpm, but that is what counts if you can keep it there.

Exactly. A 150 will rev slightly less and only really make more power down low. the 125 screams and keeps pulling in drag race mode. Now go drag race up a loose hill and you might find different results as the torque and hook up come into play.

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Yes sir TM's are FAST! My son has the 2011 TM 250MX and it's a rocket. A guy that works for me drag raced my son many times with his 2011 Kaw 450 and every time my son beat him with his TM250. I do remember seeing a dyno chart on the 144's and the TM's were at the top and the KTM's were actually down quite a bit.

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First of all, I'm glad to hear that more people are finding out what it's like to get trampled by an Italian Stallion! I think its the cool blue plastics, the frequency of light that they reflect pushes the bike faster thru time and space.

Seriously it's just cylinder port mapping. The TM has a very broad ranging motion on its power valve. When the valve is shut, off idle, she is as smooth as silk. When the valve is wide open, the TM is just a more radical motor, and sometimes that wins over displacement. My wife has a TM125en. I steal it on a regular basis, especially when it's greasy out. It's smooth down low, and RIPS up top.

I can offer another explanation in car terms. If you were to race your stock 2001 ram-air Trans Am against a 1993 Mustang with a set of huge aftermarket cylinder heads and a race cam, and high compression pistons, you would get your plow cleaned. Even though your engine is 346 cubic inches and well tuned, versus his smaller 302 cubic inches.....his engine operates at a higher efficiency level at high rpm/full throttle.

Want to change this? Look into a different expansion chamber and experiment with different squish heights. Look for a pipe with a sharper cone at the end of the expansion chamber. DEP makes some cool stuff. I also found that simply by adding an extra gasket under my cylinder, I was able to change the port timing just enough to give the bike a touch more top end power. Go too far though, and you may sacrifice bottom end / off-the-pipe power. You could also try widening the ports SLIGHTLY, like by 0.25mm and you will achieve more of a SX style torque hit. Raising the roof a bit will give you more RPM potential. If you raise the roof of the ports, do it very sparingly; you can't put the metal back once you grind it away. Again, work in 0.25mm increments there. At 10k rpm, an alteration the thickness of a piece of newspaper is noticeable.

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Id actually say its cause the TM hooked up better,

having real strong grip and making good power is a good start to any drag race..

Good call! I also noticed that. The TM has a very short swingarm, I am willing to bet much shorter than the KTM. Geometry may be working against the KTM in this department. The shorter rear end "drives under" the bike and rider more easily, planting the rear end harder into the ground.

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The 2012 TM 125MX is basically un-tested yet by major MX media anywhere. It makes so much more power according to TM that the US importer Moto-Man (909-608-0082) is not bringing in any TM144's for 2012. The 2012 TM125 has many upgrades in the engine department including an electronically controlled power-valve. The 2012 TM125MX will be in a 125 shootout by Dirt Rider Magazine that will take place sometime in late February and will appear in print about 60 days later.

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From your description, I would suggest your friend is not a very good rider? You should have never been able to Catch back up. From all accounts, from what I have seen in Youtube videos and pro racer opinions the TM125 is a absolute rocket on top end, Fastest 125 ever ridden was one comment. Also one of the hardest to keep on the pipe was another.

From my experience, in practicing starts. If you had two riders on two identical bikes, the best start is the rider that, launches straight, and shifts faster and at the correct time with a dose of weight distribution for traction.

My suggestion is not to put to much into drag racing results and have fun playing in the dirt :smirk:

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Yep thats how we do it (switch bikes/riders). Takes out most of the other variables. TM's flat out scoot!!!

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TM's flat out scoot!!!

they are engine builders first and obviously got that sorted :smirk:

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LOL K that's what we told the guy on his KX450 after he got tired of losing to my son's TM250 MX!

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LOL K that's what we told the guy on his KX450 after he got tired of losing to my son's TM250 MX!

:smirk: I rode an older TM300, kinda hated the abrupt powerband on that bike but the top end was like a CR500. Hold the F on. :bonk:

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Yeah I hear ya K I picked up the 2011 TM 250 MX for me and it was a big mistake. That thing is a pure breed race bike! Way to much RACE for me so I traded my son it for a 2010 GG300. Since then he sent the TM carb and head to Ron to make it pump gas friendly and bring up the low end power. Ron completely transformed the power output. Now it has a great low end pull followed by the strongest mid range of any bike I ever been on in my life and at 53 now it's been a lot of bikes. The bike now even with all it's power is ridable where in stock mode it just wanted WFO throttle or nothing!

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Yeah I hear ya K I picked up the 2011 TM 250 MX for me and it was a big mistake. That thing is a pure breed race bike! Way to much RACE for me so I traded my son it for a 2010 GG300. Since then he sent the TM carb and head to Ron to make it pump gas friendly and bring up the low end power. Ron completely transformed the power output. Now it has a great low end pull followed by the strongest mid range of any bike I ever been on in my life and at 53 now it's been a lot of bikes. The bike now even with all it's power is ridable where in stock mode it just wanted WFO throttle or nothing!

Yeah I was trying to ride it on slick clay base in the winter on technical stuff. Not a good match.

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Exactly. A 150 will rev slightly less and only really make more power down low. the 125 screams and keeps pulling in drag race mode. Now go drag race up a loose hill and you might find different results as the torque and hook up come into play.

The TM might be a little more tiring after a 3 hour harescramble

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