44 Horsepower KTM 150SX Two Stroke RAW - Motocross Action Magazine

#motocross #dirtbike #racing #twostroke
The 2021 KTM 125SX was our weapon of choice for the 125 Pro class at the 2021 Wiseco World Two-Stroke Championship, but because Glen Helen doesn’t want to worry about how to catch cheaters, they make the Pro class open to bikes up to 150cc. MXA already had a stock KTM 150SX, but instead of using it, I took the opportunity to double our 150cc inventory by obtaining a big-bore engine kit from KTM for our stock 2021 KTM 125SX. KTM’s 150 factory kit includes the cylinder, cylinder head, piston, power valve, combustion chamber insert, gasket control covers, ECU, control flap and rings and gaskets, all under one part number. Although KTM sells a complete 150SX motorcycle at the dealers, that bike is no different from what you get if you install this kit on your 125SX. At the end of the weekend, Mosiman got $1000 for third overall in the Pasha 125 Pro class, plus $250 in holeshot money. Plus, his 4-10 scores in the Open Pro class gave him another $300. Although he left money on the table with my mistake in the second Open Pro moto, Schnikey and he left with $750 each.
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[@matthewchevres4970]

Nice MXA! I built my 2022 husky 150cc just like this. Asked pro circuit for the josh mosiman spec, lol. We also built bottom end, sent crank to vhm for proX rod kit/bearings and to be balanced & trued for 150cc piston etc. Transmission was cryo/micro polished, cases were ported & matched, all new ceramic bearings were installed, and 250sx-f air boot installed also. Dyno out at 46.5 HP. Worth every penny imo, it's so fun & fast 👍

[@JacksonD489]

Dude… this sounds awesome! I’ve always felt like the crank mods were a must on a build like this…

[@matthewchevres4970]

@@JacksonD489 yeah brother, i agree. Especially with the 2022 125-150. Ktm used a different con-rod/bearing(s) which has been a problem for people. I will always opt for the proven & tested route as far as durability and performance and safety as well 👍

[@motominded5275]

what did that cost you if you dont mind me asking? Sounds like a 250f killer!

[@justinwhittaker3819]

How much did pc charge you?

[@matthewchevres4970]

@@justinwhittaker3819 $435 that was for cylinder porting and a custom MRX02 cylinder head insert that was made from a blank vhm insert to pro circuit"s specs. You can have it anyway you choose, it just depends on what fuel you are going to run

[@bloomerb4162]

I rode a 22 150sx for first time, most fun I've had on the track.

[@86rustbucket]

This thing looks and sounds sweet, but would love to see you guys test, just once, at a Midwest or east coast track with some mud and ruts.

[@Mr10usdad]

I bet this is a fast revving adrenaline machine! Make two strokes great again!

[@mt1885]

Wish they would have a separate 2 stroke racing series and abandon the '4 stroke nascar' bikes that tanked the sport out.

[@andy5786]

Thanks Motocross action magazine videos class👍❤️😊

[@vwsandvettes3253]

That looks like a fantastic fun time, but you hafta know what you're doing. In my mind's eye, while watching Josh at work on the 150sx, I imagined myself trying to ride that thing that fast. I virtually incurred a broken neck, collar bone, 3 broken ribs, a fractured pelvis and shattered femur 😜😅

[@jasonfalcon4052]

That’s bad bro. I shattered both my legs back in 01 from stabbing the face of another tabletop jump 140 feet away.

[@MiikeyLawless]

Ehh, you should be able to shred a 125/150 before ever moving to a 4 stroke. It gives you the fundamentals. 4 strokes allow you to ride lazily which inevitably leads to some nasty crashes. Saw it so much when I was racing.

[@bubbasouthern5218]

Music to my ears. Thank you

[@ericriedesel1338]

Love the raw vids! Would love to have a smoker again !!

[@romper4444]

who got GOOSEBUMPS watching that?!

[@Kawiboy]

That was a BLAST 👊 👍.. Sounded SWEEET.. Thnx MXA

[@superbeast-lq3ft]

That thing is a rocket.

[@rickrossi4468]

WICKED! Sounds like Fros at Lorettas Last year. Music to sting by!

[@leahrose8807]

please do a 85cc shoot out

[@jasonfalcon4052]

44 HP wow that’s impressive. That’s all I would need to smoke Eli Tomac plus 3 months of training.❤️

[@LIL.J696]

Only way you’d smoke et3 is while he is lapping you 🤡.

[@shanemoves2567]

Looks fun, sounds cool, know it's expensive

[@lucashurst4191]

Does this means that a 300sx could possibly make 88hp?

[@leane6592]

no, a 300 sx make approximately 58hp

[@ddmn3648]

possibly... but will only last a couple of laps, possibly...

[@gladegoodrich2297]

Anything's possible? Indy cars are only 2.4 leiters but make 900 H.P. and usually last 500 miles😎

[@Corteum]

44hp for this 150 is nothing. could easily goto 50+. Consider, a 250cc 2-stroke go kart can make between 65 and 75 hp with loads of torque.

[@jr6874]

I've seen 250 two-stroke dyno less than that. even my Beta 300 RR only 42hp at the wheel

[@foobarmaximus3506]

Yeah, this is bullshit. I know it doesn't have anything near 44. 24, maybe. Maybe.

[@jaymontgomery3330]

@@foobarmaximus3506 a stock SX 125 had 38 HP,. So yeah I believe that 150 makes 44HP.

[@mulisha0351]

@@foobarmaximus3506 this isnt a cr125 or yz, the 125sx already makes 38..

[@Reubambam247]

@@foobarmaximus3506 41hp stock, I've owned two, they're rockets

[@DB-fn3fz]

@@foobarmaximus3506 pretty common for shift kart motors make 47hp from a 125 2-stroke. I don't see why 25 more cc's in an mx bike would be that unbelievable.

[@markallen6818]

Would Love to have one of these since My all time favorite Bike was a Suzuki RM 125N.Still hard to believe they are getting that much HP out of a 150cc motor.What does it weigh about 210 lbs?I probably don't want to know what it costs.

[@Reubambam247]

I'd like to know what motor work was done to gain the extra ponies. My last two bikes were 150's, both had pc exhaust and vented airbox and were rocket ships, another 3-4 hp on top would've been welcome! Having said that I actually prefer to ride a 125 but being the vet I am the 150 helped me with bottom end pull.

[@abracing199]

head work and porting

[@raniklestari3645]

Woouuuwwwww....💪💪💪❤️🙏

[@Jimmy_Watt]

Bravo.

[@scottyd2262]

Boyesen doesn't import the Supercooler into Australia anymore and that really upsets me. I've purchased many Boyesen products since 1983 here in Australia and now that l ride a 4 stroke and can't buy their reeds anymore (every 2 stroke l've owned had a set) I'm devastated that l can't get a Supercooler for my new Husky.. Plus they don't make them in blue either.. If anyone from Boyesen reads this please bring them back to us in Australia also make the blue one again.. Pretty Please.. I'm begging you ! 😢

[@paultselembis4255]

Just get v-force 4r there better

[@scottyd2262]

@@paultselembis4255 I would but l ride a 4stroke now bro.. I've heard nothing but good things about V-Force though.. They sound great

[@paultselembis4255]

On my yz they made massive improvements as stock yamy reeds are garbage on my kato it made a difference but not as huge as yamy but stock ktm are not to bad from the get go

[@jpesicka492]

If I had a mili, getting one of these, a 300 exc and a 350exc and 350 sx

[@mirkolo4703]

does it really have 44 hp?

[@ddmn3648]

44 caralhos!

[@jmzochsnrtr]

How about putting the 225 class back where it belongs in the motocross scene. Making these bikes is for what purpose other than personal like..?

[@markday2198]

I thought the 150 had 3 hp more than the 125 ?

[@KennethColeJr]

I hear the ktm 150 blow up

[@anthonys5170]

Word what about a worx 200cc

[@herbrachel3663]

That's the yummy stuff

[@lottolinks6394]

nothing worse then a guy sitting there revving a cold bike.. thinking he's doing gods work

[@goldmx1229]

I prepared myself economically to buy a 150sx 2023 this year, But for my luck they decided not to make it this year.

[@Reubambam247]

Don't buy a 22 either, issues with cheap con rods, they have recalled them and replaced the CDI to lower the rev limiter.

[@goldmx1229]

@@Reubambam247 I believe you, Im in a ktm 125/150 owners and they are complaining about it on the 2022, Thanks for reminding me.

[@Reubambam247]

@@goldmx1229 bit naughty of KTM but I can understand swapping out the CDI instead of the rod, imagine the cost of replacing and rebuilding all those rod in 22's sold...

[@michaelcaddell8520]

@@goldmx1229 I'm a 25y/o vet B/C rider. The 150 is hands down the most fun bike I've ever ridden. Definitely takes tap dancing with the shifter and keeping the revs up but that's what makes it so much fun. Still not quite as fast a 250f but it's definitely more fun and much cheaper on top ends, no valves, etc. I definitely recommend getting the 19-21, stay away from the 22 due to the bad crank bearings.

[@goldmx1229]

@@Reubambam247 True!

[@pedrofernando176]

✌👍

[@builtfordtough4499]

sounds lean...

[@fullnoyz7670]

*mean

[@randyroberts4239]

44 hp is what 250's made in 1990....

[@SpeedandPower]

In 1990 all 250's had 52 to 55 hp 😉

[@mikebrown41182]

@@SpeedandPower Haha no. A modern KTM 250 sx makes 49 stock.

[@SpeedandPower]

@@mikebrown41182 i dont know.. but in the 90s a 125 had around 37-40 hp, a 250 around 55 hp, a 500 around 65 hp... my 1991 KTM MX 250 has 56 HP

[@mikebrown41182]

@@SpeedandPower Give us some sources to these claims. Cause it aint true in regards of the 250s.

[@SpeedandPower]

@@mikebrown41182 its hard to find hp of mx bikes.. in mx magazines in the 90s i have read was often written the hp.. but in this yt video "KTM 1991 Model Line Promo" about the 1991 ktm line up its said that the 1991 exc 250 has 52 hp.. and its well known that the sx versions always are more aggressive with ignition and had a few hp more then exc models.. Believe me, it is true... btw 45 hp has already my 1984 Maico SC 250

[@foobarmaximus3506]

Bullshit. It doesn't have anything like 44 Hp. LOLOL

[@xfdfff2620]

Around 40 in reality

[@Lee-mx5li]

No way on this planet that THAT 150 is putting out 44hp... watch several times it runs out of hp to continue a wheelie.. NO WAY!!! LMAO

[@miikasparf2613]

Soo you think the rider is there to pull wheelies 🙈😆

[@Lee-mx5li]

@@miikasparf2613 1000000% not.. My point is with "A" true 44hp to 125 frame weight ratio, IF HE'S PUNCHING IT, THE VIDEO WOULD SHOW HIM CONSTANTLY BATTING THE FRONT WHEEL FROM LIFTING which the video clearly does not show...

[@Corteum]

@@Lee-mx5li KTM 150 puts out 43hp stock. so 44hp isnt implausible.

[@xfdfff2620]

@@Lee-mx5li you can make any bike not wheelie with good rider but this bike is probably not pushing 44 whp but rather closer to 40. Dyno they used shows high figures