KTM300XC Build Project

[somepunk22]

From the 2014 KTM manuals. They are so close I think I'm going for a Husky TE300 for next year. XC suspension with XCW gearbox and lights.

XC XCW/TE
15:30 14:32
16:25 16:26
20:25 20:25
22:23 22:23
25:22 25:22
26:20 26:20

 

[mtn-doo]

I am pretty sure that the xc and xcw share the same ecu and head. What are peoples thoughts regarding the sx verse 13 xc ecu? I rode for the first time yesterday with the xc ecu and I think it may be a bit milder than the sx box. What I mean is the sx might stay on the pipe better. We were in 12-18" of fresh cascade concrete, 40 degrees, 6K elevation, high humidity, so those factors sould have been playing against me. If I had time today I would go back with one size smaller main jet and a spare ecu and go do some seriously fun testing. 300 LT owned the hill yesterday though! The motor that Cycle Playground built for me has some serious torque. Feels and sounds like a 500 compared to the stock porting with sx head. IMHO of course!

The two do not share the same ECU. It is a "non point" though. Two 8mm screws and :30 second change for the more aggressive map. The two bikes are nearly identical. ECU and gear box... slight differences. Summer , the XCW would be the winner. Winter and a couple easy changes when you convert, would be a great two-fer.

Michael at Cycle Playground does great work. Send him a cylinder and head, with a few extra's you will have a serious performer!

 

[mtn-doo]

I am pretty sure that the xc and xcw share the same ecu and head. What are peoples thoughts regarding the sx verse 13 xc ecu? I rode for the first time yesterday with the xc ecu and I think it may be a bit milder than the sx box. What I mean is the sx might stay on the pipe better. We were in 12-18" of fresh cascade concrete, 40 degrees, 6K elevation, high humidity, so those factors sould have been playing against me. If I had time today I would go back with one size smaller main jet and a spare ecu and go do some seriously fun testing. 300 LT owned the hill yesterday though! The motor that Cycle Playground built for me has some serious torque. Feels and sounds like a 500 compared to the stock porting with sx head. IMHO of course!

You are correct. The three stages of ECU are XCW = mild, XC = moderate, SX = agressive.

 

[thejean]

I have the SX head and ecu on my 300. I think I'll take it off for summer as its a beast! I can only imagine what porting would do on top of that!

 

[x2468]

So you need to pay for membership on this forum to read an entire thread? wtf

 

[Draxxus]

I converted my 250 xcw to the 300 sx , for summer riding I want to tune it down a bit but want to keep the 300 jug and head on , does any one know if I can run the 250 ignition ?


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[mtn-doo]

Yes, just swap back to the XCW box and your green exhaust spring. It will tractor and be smooooth.

 

[Gros Chien]

I was quick enough to put my hand on a 2015 SX LT for next season and will build my next year snowbike with a Husky TE 300 .

 

[Draxxus]

Yes, just swap back to the XCW box and your green exhaust spring. It will tractor and be smooooth.

Even tho it was a 250 ??? Just wana double check


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[mtn-doo]

Yes. It only pulls timing. You can swap back and forth.

 

[slednut34]

Building ktm 300 with sx head cdi box and pipe. What size billet smart carb 36 or 38? And what is a good egt at wot thanks.

 

[mtn-doo]

Building ktm 300 with sx head cdi box and pipe. What size billet smart carb 36 or 38? And what is a good egt at wot thanks.

You want the 38MM Carb. The Smart Carb is super lean and clean. You will be startled at first. We are so used to slobbery tuning. The WOT testing on extended WOT pulls is 1270 to 1290 EGT and are normal and safe. Those EGT's are coupled with a 14.0 AFR. That is peak and Ideal for all around use being on and off the throttle on dirt. On snow, we run them WOT a ton. Not like a bike on dirt, so if you want to be in the 1200 / 1250 range, tell Corey or Liz to send you a metering rod two sizes richer.

 

[slednut34]

Thanks mtn-doo great info! Just tested my bike and it was 1260 for 20 sec wot.Thought it was a little high.But I see it's right in the ball park. thanks again!

 

[mtn-doo]

You are perfect at 1260 WOT. Adjust the rod for a clean idle and crisp throttle response then you are set. You never need to touch it again. Winter / summer , any elevation or temp. It will stay perfect. Pretty amazing.
Remember adjusting the rod for idle will not effect your 1260. Think of the metering rod as the pilot circuit. Congrats

 

[Leaf27]

Do you have any vids of this bike in action?

 

[mtn-doo]

Yes, It's buried a few pages back. Here ya go.

https://www.youtube.com/watch?v=YK1m2wbGLZU

 

[Leaf27]

Yes, It's buried a few pages back. Here ya go.

https://www.youtube.com/watch?v=YK1m2wbGLZU

Randy, that bike looks like a blast to ride. I don't think the video does it justice. At around 7:30 on the video you go back up, how does the bike climb in the deeper untracked areas through the trees?

 

[mtn-doo]

It does excellent. It "is" a blast to ride. If you like to be aggressive, always WOT and whacking the clutch, you will LOVE it. If you push it that way, it will out run a 450f through the trees. If you want a hill climber, an LT on a Turbo, etc is probably a better choice. If you want a super light, quick, fun "tree rider", the 300 is excellent.

 

[mtn-doo]

Here's a little clip of the first day out testing gearing, jetting, etc. It still had the stock PWK carb and factory jetting. The snow was cold, dry and deep. My friend Steve that was on the 500XCW with a LT said he had to poach my track to keep up. I was only half throttle getting to know it's particulars. Later with the gearing dialed in and a Smart Carb it was super quick.

https://www.youtube.com/watch?v=pC8bAh0JspA

 

[wwillf01]

Hey guys,

I received a brand new 300XC for a turn-key build. Thanks to the owner, he agreed to make it public. It will be a great motivator and encourager for a lot of people considering a snowbike in this category. There is a lot of interest on smaller cc 2-strokes. Snocattin's 2006 YZ250 is a good example of how well they work, and how fun they are! Listen to the vid!..Ha! There are literally thousands of good clean 250 class MX bikes out there. With a few simple modifications, they can give you a ton of fun all winter. Easy to operate and practically maintenance free. With about 50HP and an ST or SX kit, they are a ton of fun.

This particular build will include everything to make the most available in the 250/300 class.

#1- New 2013 KTM 300XC
#2- 300SX Head, 180psi
#3- Cylinder porting; port and polish
#4- SX- CDI Box
#5- PC Platinum-2 exhaust system
#6- E-Line Carbon Fiber Pipe Guard
#7- KTM "red" power valve exhaust spring
#8- V-Force 4 Reed Block
#9- APT Cast 38MM Smart Carb
#10- Custom Neoprene Carb Jacket
#11- KTM electric Carb Heater
#12- Custom Boondocker clean air intake system
#13- Rekluse Core EXP Clutch
#14- 70 C KTM Thermostat
#15- Fastway/Pro Moto, Adventure Pegs, Risers and Guards
#16- Moose Racing Grip Heaters
#17- Stinger LifePO-4 Battery, 219 CCA
#18- UFO Plastics
#19- Graphics

This will produce a very aggressive pkg with HP safely in the mid 50's. When mounted to an ST Kit, it will be a real fun ripper.
The bike is in the shop and all parts on order. Next week will begin the project. The build process, all tuning and testing will be posted here. Stay tuned!

Who do you recommend for the port and polish on a 300?


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