2015 YZ250 Build Thread

Well, I stopped being a puss and threw the cash down on a 2015 YZ250.  I'm a salesman at the dealership I work at and we didn't have any more 250's in stock, so I had to order a freshie, straight from one of Yamaha's distribution centers in California.  We are located on the east coast in Orange County, NY, so it will take approximately 2 weeks to receive the bike.  I will literally be building the bike straight out of the crate it was shipped in.  


Since the bike is en-route, I took the down time to start ordering the parts I will be installing.  

A few cool companies decided to help me out with the build, so I don't have to spend QUITE as much money.


These companies are:


-Dubya Wheels (Talon Evo Wheelset and Talon Sprockets)


-Motohose (Blue Rad/Carb Hose Kit)


-Hammerhead Designs (CNC'd everything.  Pretty much every part they make for this bike) 


-Mika Metals (Oversize bars and a set of their grips)


-180 Decals (Graphics Kit and Seat Cover)


-Factory Connection Suspension (Getting the boingers' all dialed in)


-Western Power Sports


-Tucker Rocky Distributing




Tucker and WPS will help me with the all blue UFO plastics, the FMF factory fatty pipe and shorty silencer, Lightspeed carbon fiber glide plate, chain guide and rear caliper/rotor guard, Dunlop MX32 front and rear tires and Motion pro LiteLoc's, rim tape and tubes.  That's pretty much all I can think of off the top of my head.  I'm sure I'll throw some more cash at it as the build goes on.


Because I'm building the bike out of the crate, I will also be going over the entire "race prep" of the machine, as you should properly do to a brand new bike, as well as the installation of all the go-fast parts.  My goal is to post a ton of pictures as the build goes on, because I've always wanted to post an in depth build thread.   



To try and save myself a little bit more money, I will entertain selling the stock parts off the bike.  I won't need any of them, so for the right price, I will sell pretty much everything stock that I don't need to whoever wants them.  


Stay tuned, because parts are starting to roll in every day!  Hop you guys enjoy.  

Edited by 9formula7skidoo

Let me know when you start to sell some parts. I may actually be interested in your plastics.





Yup. Interested in parts and watching this build. "Thou shalt not covet." DOH!


Should be interesting..

Looks like its gonna be a cool build. If buddy ahead of me doesnt want the plastics. I will buy them. Thanks.

I was told the squish is wide from factory and timing can be out of spec. Somthing to think about. Free and cheap mods

Edited by IntoTheVoid

Some parts started to roll in yesterday afternoon.  Small stuff, but its a start...




A few of the plastics started to come through from Tucker Rocky.  I'm going with UFO and all blue everything.  I'm really not a fan of the white number plates on the '15 for some reason.  I should have the rest of the pieces by the end of next week.  




Mika grips.  Nothing special.  Still waiting on the bars to come in and I should see them at around the same time as the other plastics.




MotoHose kit came in also.  I've never seen any performance benefits from these like some people claim, but I did finish a race after the header smashed up against one of the hoses.  It cooked the hose, but never leaked, so they do seem to have better heat resistance than stock.  They do however, look trick, fit great and match OEM colors perfectly.  




I'm going to try out these MX32's.  Apparently it's what all the kids are running these days.  I left Dunlop behind because of the horrible wear I witnessed on my last set of both MX51's and 52's.  My buddy told me these lasted longer.  I'll try anything once.  I chose to run stock tire dimensions, which are 110/90-19 and 80/100-21.




I also picked up everything needed to throw the tires on the wheels.  Tubes, Motion Pro LiteLoc's, and Motion Pro rim tape.  With the all plastic rimlocks and the rim tape, changing tires is easier and I haven't gotten one flat since I started using the combo.  The tape stays put and makes installing the tube a breeze and if you do want to pull the tape off, there's no nasty residue on your expensive wheel like you would get with duct tape.  Its a bit more money than the standard stuff, but I think it's worth it.  

Edited by 9formula7skidoo

The wheels were just ordered from Dubya.  The Talon "Evo" wheel is only available with the "Evo" wheel set and apparently the guys at Dubya build them for you, before shipping them out.  I figured Talon built them, then shipped them to Dubya, but I was incorrect.  That's actually pretty cool that the guys that build wheels for all the top pro's will build a regular customer's setup.


I have to do more research on the timing and squish.  I didn't think setting the squish was free.  I thought the head had to be milled, which costs cash lol. 

Edited by 9formula7skidoo

Having your head cut to properly set squish is cheap, especially compared to everything else you are doing. I wouldn't skip that set.

Doing the squish and porting will yield more results than any pipe system you throw at it. 

Been there, done that.

I'm with Tony. The squish was the last thing I corrected. After putting pipes and reeds. Should have done that first. Think it was $100 or so for the work and shipping both ways. Definitely worth it.

I'm with frettie and tony, get the head corrected, and rejet it. Factory machining tolerances and conservative settings means there is near zero chance it's currently right.

Assuming your suspension springs are right, and your aim is faster lap times riding for longer with less effort, then in my opinion the head and jetting is the best $200 you can spend on the bike. Makes a massive difference to the broadness and consistency of the power delivery.

Next best $ spend would be a Tusk oversized front brake rotor kit.

Who would you recommend to do the squish band?

If I'm going to do that to my 06 I feel like it would be money well spent to have the cyl replated and ported all at once. Could they set the head to work well with Av gas? 100LL is easy to come by and comparable cost wise to premium for me.

I will absolutely look in to getting the squish set properly.

I just heard from our Yamaha rep and the bike is actually coming from the New Jersey warehouse, instead of California. So if all goes well, I should expect to see the bike no later than Thursday.

Rb designs is very widely known to do great head work and there are nice instructions on their website on the process to measure it.

Edited by mlcompound

Who would you recommend to do the squish band?

If I'm going to do that to my 06 I feel like it would be money well spent to have the cyl replated and ported all at once. Could they set the head to work well with Av gas? 100LL is easy to come by and comparable cost wise to premium for me.

If you are going to use high octane fuel, and want a broader power spread at the expense of some peak power,then you could considering leaving the head untouched and have the base of the cylinder shaved instead. Any motor machining shop can do that quickly and accurately. Or just spend $20 for a thinner base gasket and you're done!



I have compiled a list of take-off parts that I will be selling.  If I had unlimited funds, I would be keeping all of these as spare parts, but It would be better for me to try and sell them and re-purchase them in the future should I ever need them.  


The list includes:


-Front and rear wheels

-Chain and sprocket set


-Stock pipe

-Stock silencer

-Seat cover

-OEM plastics - SOLD

-Stock brake pedal and clevis

-stock shifter



I may sell the stock brake rotors, depending on what kind of deal I find on an oversize front rotor.

Edited by 9formula7skidoo

Prices? I am interested in stock pipe.

Also interested in the stock pipe.

Prices? I am interested in stock pipe.


Also interested in the stock pipe.

Shoot me a PM with an offer.  I really have no clue lol. I don't even have the machine yet.

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