The Ultimate 300 Build Thread - 2014

Hey guys, I have had so much fun with the various 300 projects I decided to pull out all the stops and build the "Ultimate 300" this year for my personal ride. It will travel to various dealers and be used this season as a company/dealer demo bike. There is a lot of momentum and enthusiasm for the lighter, quicker, sporty tree banger. This thread can be used as an aide for many different projects. The YZ295, the ESR325, etc. would all be great candidates. I have tried to cover all of the details with this years focus, a mid-sized two stroke. Another point to keep in mind is the objective of a platform like this. The goal is not to be the first guy to the top, or the high mark for the day. This platform is for the guy who sold his 163" and opted for the 154" sled to "work the trees" and enjoys that approach. A basic description of the capability and personality of this type of bike is this; They produce +/- 58HP, they need and love to be ridden aggressively, elbows out and whacking the clutch, they are super quick and sporty, they "feel" 50lbs lighter though actually about 20lbs, which is huge!. There is no "gyroscopic effect", rotating mass of the 4 stroke engine, the "feel is completely different, they are telepathic in handling, and "flickable".

I will post all links, addresses, photo's and info as I move along. Once the snow flies, I will post thorough footage of action in "all types of conditions". The over-view of the project is listed below.

#1 - 2013 KTM 300 XC
#2 - Millennium Tech, Eric Gorr porting
#3 - Slavens Racing, Star Head with optional Dome inserts, low and high altitude options.
#4 - KTM 250 SX CDI Box
#5 - Light weight exhaust valve spring
#6 - American Performance Technology, 38MM Billet Smart Carb
#7 - Avid Products, Billet Carb Heat system with true-bypass Billet Thermostat system with the 130F Stat.
#8 - Pro Circuit Platinum - II Pipe with 304 silencer
#9 - SLP Ceramic Coating for the pipe.
#10 - KOSO, fast response EGT
#11 - Rekluse 2014, 3.0 Clutch with custom weight and spring tuning
#12 - Heavy Duty 280 Belleville clutch spring
#13 - IMS, 3.3 Gal Gas Tank
#14 - Pro Moto, Adventure Pegs, 2" Riser and Guards
#15 - Boysen, "race team" custom reed block and reeds
#16 - .56 Fork Springs
#17 - EK, RXO Super-moto racing chain with ZST. Light weight sealed racing chain with zero stretch technology. Guaranteed no adjustment for the first 1000 miles.
#18 - Shox sox fork seal protectors
#19 - Moose Racing Grip warmers
#20 - Yuasa YTX 7S Battery
#21 - Motion Pro, "slide wright" T3 Throttle cable
#22 - Custom intake/air box
#23 - E-Line Carbon Fiber Pipe Guard and Skid Plate
#24 - UFO Plastics with "super-moto" front fender
#25 - Custom Graphics by Dirt Digits

That is the over-view of the chassis. I have light weight and efficiency mods going into the Mountain Horse kit that will be addressed later. It will be paired with an ST Kit.

Fuel, oil, tuning etc will all be covered in time. Stay tuned for a super exciting and fun project. Building this bike will be half the fun, dodging trees at WOT will come soon enough!

Jimb said:

You are going to run a rekluse? What's your experience with them on snowbikes?

Also where'd you find the .56 springs?

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I have a ton of time on both. You don't "need" the Rekluse to function properly. I have played with some custom weights and springs to get the "braaap" engagement to sync with coming on the pipe like our sleds. I found the combo this year. With the Rekluse tuned for the motor, you get engagement and engine "together". It will be stupid fun. .... and really fast in the trees.

Slavens Racing. Jeff is a suspension expert. Tell him you want .56 springs. Back your rebound off to about mid setting. Super plush but zero spongy sag or bottoming. Keeps your bars up and weight back. A must do...

Phase one is tear down. Everything goes, all plastics, gas tank, air box, sub frame, pipe and silencer, hoses, head stay, head, reed block and intake, Carb and cylinder for starters. Need to ship the cylinder off to Millennium Tech for Eric Gorr to get the porting done. This is also a good time to get some measurements from the piston skirt for the EGT location in the pipe. The pipe gets sent off to SLP in Idaho Falls for Ceramic coating. Waiting for parts is the hard part.....

http://www.eric-gorr.com/

https://www.startinglineproducts.com/

I've tried a couple as well as port timing by porting and decking. The objective was to simply lower port timing and boost low end. The result was interesting but not surprising. As we discovered with big 4-strokes, boosting the low end and bottom end torque sounds good, but on the mountain a bike with less overall HP that revved higher, farther, and carried HP longer would spank the bigger "low end engines". Hummm? Interesting.... The Snow Bike loves Mid/High and lot's of rev's. Have him port for "Mid to High". We've realized we don't actually "short shift" and grunt around the mountain, slowly, in a gear too tall. LOL When it's game time, we're pushing hard in the mid/top end. The "Mid/Top porting gives an overall boost in peak HP as well.

thejean said:

I wish there was a decent starter option for the 300. I've gone through two starters per year since getting the bike. Also on my 3rd bendix. Ugh.

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Seal the drain hole in the bottom of the ignition cover with a dab of "right stuff" then add 2oz of 5wt fork oil in from the top. Insert a syringe behind the starter gear. Add 2oz.

Summitseeker said:

I have a very similar build going on except my 2014 is a XC-W six days and will be paired with a 2015 ST.

I have either purchased or installed almost everything on your list with the exception of the throttle cable, porting, (doing it myself), custom air box, chain, tank and I went with V4 Force Reeds instead of Boysen.

Questions:

1. Is there anyone that makes these "custom" airboxes for purchase? Is it critical to have one?
2. Is an EGT necessary or is it just a recommendation to stay safe?
3. Is my wide ratio tranny going to work OK?
4. Anyone know where I can find a white KTM supermoto front fender? Nobody seems to make one for a 14 yet. Acerbis only makes one up to the 13. The 13 fender will not work with the 14 headlight.

Thanks!!

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1- The air box is a "must". They are simple to do and will be the best mod you have. I have seven 300's in the shop now. Every one will have "two boxes", a modified winter box and their stock box for summer. Easy to do and not a cost factor. I have posted the box and filter mod in several locations with builds. Also, I will re-post the details and pic's with this project.
2- The EGT is not mandatory. I use it for testing and tuning various modifications all season. When in doubt, pump your throttle a few times. Also your first few rides do some plug checks after some long, WOT pulls. Just like you would on a 2 or 4 stroke, read your plug during initial tuning. An EGT or an AFR make it easier for precise tuning.
3- your wide ratio trans will be the biggie.... no go. Third gear is dificult to gear around. Super low to make it work gives you a road speed of about 30mph. Gearing up to make 1st and 2nd your primary using gears makes 3rd even worse. That will be your biggest headache.
4- I use any "universal" fender that is not bike specific. You drill your own holes and I also fab aluminum brackets and design a custom mount.

wwillf01 said:

What advantage do you get from ceramic coating the exhaust.... Less of the cooling effect from the snow?


Sent from my iPad using Tapatalk HD

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Yes, and weather protection, also add's a little "bling" for a nice show bike.