New KTM 300 SX is going to be a great snow bike

[CATSLEDMAN1]

My riding partner bought one for next years snow bike project. The big upside is riding it in the woods the last couple of weeks. Best motorcycle I have ever ridden. Light, agile, best controllable power I have ever experienced, smooth and quiet, and quick......wow.
Swapping bikes my Ktm 200 with lots of mods feels heavy and slow, a 450yz feels like really dated. Going to be fun to see it on the snow.

 

[eric82930]

Nice. What transmission is in it? I rode the xc and was impressed for out of box power. I'm sure hc head will be even better.

 

[Sheetmetalfab]

Yeah i rode a 2023 300XC also.

Impressive at all rpm ranges.

Really shines on top compared to any other 2 stroke I’ve ridden.

Long smooth legs.

 

[schwany31]

My 300xc worked awesome with a 120 CMX, the TBI pulls for days

 

[dooman92]

schwany31, how does the fuel usage of the 300 tpi on the snow compare to a 450 ? will it hang with a 450?

 

[M5-]

Back when I was riding my CR500 it was a love hate relationship with the 2T. I would love to try a modern injected 2 stroke. That said my built 4T is pretty strong but if I could drop some more weight on the total package without any loss in performance that would be pretty awesome.

M5

 

[BigAir]

schwany31, how does the fuel usage of the 300 tpi on the snow compare to a 450 ? will it hang with a 450?

You and schwany31 said 2 different things. You said TPI and he said TBI. Probably not a lot of difference in fuel usage, but probably some.

 

[eric82930]

Yes and be specific about your ECU programming when discussing fuel mileage. There was a huge change in factory tpi maps from 19 to 20 from super lean to super rich. The factory tbi seams about right in my very brief ride. All my carbed 2 strokes except the brc have always used slightly more fuel than the 450 so it's probably never going to be less but could be close if everything is perfect. My brc500 used much more add I can't seem to get it better. It just runs off the pipe so often because it's so big it doesn't need to. And a 2 stroke running off the pipe is not in the efficiency zone.

 

[NEWDUCK]

I love my 23 300sx. I havent compared it in the snow but in sand a new 450 will pull away from it on the long hills. Id guess the snow youd see the same results. Ive heard the new yami 450s are insane on a tune.

 

[CATSLEDMAN1]

Its the two stroke power delivery that will make the 300 sx a go to bike. 4 strokes cannot will not and won't get up on top of the snow. same reason 4 stroke sleds are so popular with deep snow riders.

 

[teal_210]

I have a 23 300 xc and a 23 450sxf. I was hoping to put a Mtn. Top on the 300, but after switching back and forth between the two I just can't see how the 300 is going to be as good or even close to the 450. I'll probably still give it a try, but not expecting much out of it.

The 300 is nice, but it just doesn't have the raw power of the 450.

 

[CATSLEDMAN1]

Some guys will fool with this engine, it is not the xc cylinder, has close ratio 5 speed , and has the button to start. I see u tube videos's about new head etc that kick it up another 5-10 hp, getting in the range of good running 4 strokes, best feeling 2 stroke power delivery feeling in my memory. snappy even at low rpm.

 

[ravenous]

Well, Catsledman, normally I take your thoughts and advice as the undisputed truth. : )
But I'm not sure about this, yet.
I would love to get back on a 2 stroke snowbike again. I miss mine in many ways. I spent a lot of
time dialing my KX into perfection and I believe it was as good as a 500cc dinosaur could get.
Then I switched to a 450 and right out of the box it was better in almost every way. Yeah, my KX
made more power, but the 450 revs like crazy, which on a snowbike I think is crucial. It has a much wider
usable rpm spread.
One of the 450's major downsides is the horrible noise it makes. Its exhaust sounds like garbage. My sledhead friends
call them fartboxes, and they are right. The 2strokes are way quieter and sound musical in comparison.
Our snowbikes are pretty anemic, and I think the type of power they make is crucial to their performance.
I look forward to hearing your reports on the new 300 in the snow.

 

[NEWDUCK]

Some guys will fool with this engine, it is not the xc cylinder, has close ratio 5 speed , and has the button to start. I see u tube videos's about new head etc that kick it up another 5-10 hp, getting in the range of good running 4 strokes, best feeling 2 stroke power delivery feeling in my memory. snappy even at low rpm.

First ive heard the xc runs a different cylinder. I thought the TBI SX/XC engines were identical besides the 6speed

 

[teal_210]

First ive heard the xc runs a different cylinder. I thought the TBI SX/XC engines were identical besides the 6speed

That's my understanding also, the 23 sx/xc are the same motor and mapping except for the transmission.

Mine is currently getting a new tune installed, hopefully that will cure the rich start-up. If that gets corrected I'll be much more optimistic about it's use in the snow.

 

[NEWDUCK]

That's my understanding also, the 23 sx/xc are the same motor and mapping except for the transmission.

Mine is currently getting a new tune installed, hopefully that will cure the rich start-up. If that gets corrected I'll be much more optimistic about it's use in the snow.

Are you getting a custom tune or the updated factory one that just came out?

 

[CATSLEDMAN1]

I sure can't say what the internal engine differences are unless I had both on the bench. Been told by KTM mechanic its different, and part numbers are different, time will tell. What is different riding this model is the low to high very quick throttle response, can put you on your head in the dirt, I think that feature of the engine will make some snow bikers happy. The transition to snow bike is under way, mostly planning right now, made three head exchangers for the two strokes in the riding group, heated bars and thermostats and on and on will take until the snow flies.

 

[teal_210]

Are you getting a custom tune or the updated factory one that just came out?

Did the factory update. Bike runs a little cleaner and definitely has more power but getting more spooge out of the exhaust. It isn't quite as rich on first start up now, but still takes more than I'd like to get it cleaned out and warmed up.

 

[byeatts]

schwany31, how does the fuel usage of the 300 tpi on the snow compare to a 450 ? will it hang with a 450?

No , The reason is 2 stroke run at several 1000 .s less rpm then the 450, typically 8-8500 rpm and the 450 runs to 12000 rpm ,the 450 has far more track speed when in same gear / ratio as a 2 stroke. the Over rev on the 450 gains another 6-8mph typically in track speed.. My shop builds bikes and over 275 300,s over the last 10 years. I am a 2 stroke guy for extreme enduro riding but the 450 will outperform a 2 stroke on the snow due to the Over rev.. Its a good choice if ewe wish to turn back to a dirt bike for summer but a dedicated perfectly setup 450 will make a better snowbike . Even our CR500 custom snowbike makes loads of torque cant achieve track speeds of the 450 due to its over rev potential.

 

[eric82930]

You can't really say that a 450 is always better performance. Many many 300s are way down on peak horsepower and don't rev well from the factory. But my 60 horsepower 300 will have no problem with an average 450 and my 500 BRC can pull a gear higher than a 450 and doesn't need to rev to do it. But a perfectly tuned 55 horsepower 450 will need a 60 horsepower 300 to take it because the 300 is much narrower and same goes for a 500 would need to be 65 to be in the game because the power is even more narrow than a 300. I actually use the clutch a lot on my BRC so if that's not your thing you better get a four stroke and don't shift until the valves float. I have a perfectly tuned 450 and an carbed 300sx and a 360 super mod and a 500 BRC. I can ride anything I want and they all do just fine other than the 450 uses less fuel and it has a long track so I just don't enjoy it as much and the sound is ridiculous even with a quiet muffler. The 450 stays in the garage most of the time unfortunately but it's a great bike and anytime I have a beginner along I put them on the 450.