2017 Superhero Builds Yamaha's YZ450FX and YZ250

CATSLEDMAN1 said:

I would like to see you setup the 250 yamaha with the small yeti and ride it a few trips with stock hp, and turn it over to a 150 lb rider part of the time. Lots of interest in a setup like that for new young riders / novice women riders.....how good can a light bike and kit work.

Them bring it in for engine mods and give us your seat of the pants impression on the mod steps and when you hit the sweet spot, even if its before all the money is spent.

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I think that is a great idea!!!

Les, do you and Terra want to make an early season trip out here and have her give it a go?

Thor's Camso 129 system arrived yesterday, and we got it uncrated and on the scale.














The design of this system is very different from the others we have used. I am no engineer so I can not tell you good or bad until I ride it.

As you see the pictures, and form your opinions, just remember that you are not looking at a $8999 Yeti. You are looking at a $4799 Camso. I believe this system is targeting the entry level price point, and may ride well for the money. So just keep and open mind. It is the same as looking at a Duramax crew cab Denali and only being able to afford a gas burning V6 2wd single cab pickup. There are definite price points in the market now.

Wonder Woman and Captain America go suited up for duty today!!!



This was an awesome father son build!!! I had to share:

Here is where it all started:

Going back to November 16, 2016

We picked up the new 2017 Yamaha YZ450FX's (2 of them) and the YZ250 2-stroke from Tri-City Cycle in Colorado.





We had made the decision to build a 2-stroke this year after riding a friends 2-stroke with a Yeti last year. We love the 4-stroke platforms, but need some angry, pissed off, hair on fire 2-stroke fun some times also.

Yamaha made some changes to the 2017 YZ450FX that we liked, such as a low fuel light, and some we were not sure of, like the elimination of the kick starter. You can purchase the kick start upgrade kit and install it on the 2017. The majority of the bike stayed the same as the 2016 we fell in love with last year.

Wonder Woman was the first to get built:

Our goal was build a very light weight, extremely flickable, ride that is fast, but rideable for all. I wanted to rip with my hair on fire shredding plastic through the trees and have it tame enough for a woman to ride and enjoy the weight savings.

Planned: GYTR 300 big bore and 2017 120 Yeti Snow Check ( full titanium shaft package )



She came out beautiful in all of her Pink, angry, glory!!!!!!

To start it was the teardown. She never even go the chance to start before the build started.



If 250cc to 300cc was the plan then an ERS 345cc big bore had to be better. So this is where we start. Top end tear down and install the ERS 345 kit.





Here is the stock 250cc piston in the 345cc cylinder:



Then the two pistons side by side:



The install was easy and the motor went back together quickly with Yamaha GYTR reeds, pipe with a carbon fiber guard to prevent "cold pipe", and silencer. The carb was jetted and the carb heater and thermobob was installed. Along with the EGT guage and coolant temperature gauge. The intake was handled with a Yeti intake.

It is now time to add the Promoto Billet Fit 1 hand guards, w/ screw in bar ends so nothing moves when we smack a tree hard. Then we set the bars on a pair of Promoto Billet risers and install the risers in the rearward holes in the upper triple clamp to get us into the correct riding position. The YZ250 does not have enough power to run heated grips, but there will be a set of Raze Motorsports liquid heated bars in her future.



Once we were done with the controls it was now time to dedicate some time to the front forks. Rocky Mountain Snow MX has developed the best front fork set up that most of our customers have ever ridden. We build custom replacement forks for KTM's and do RG3 snow bike valving and RMS MX custom springs for a true perfect snow bike front suspension. In most other brands we valve and spring the stock forks for the customer. The Yamaha forks are great forks that do not need full replacement like the KTM 4CS and AER forks.

If you have ever taken a Sag measurement on your snow setup you will find that doing work to your forks is a MUST. We have found that most snow bikes have between 40 to 60mm of static sag. (no rider on board) You are using so much of your front fork travel just by the weight of the bike. We feel that the static sag should be much less that that. A stock wheeled bike has about 100lbs. under the front tire. Most snow bikes have double that. Are you seeing why you need our fork set up????



Yeti changed there front spindle this 2017 season to be a little shorter than last year. The dealers that were just bolting these kits on an sending the customers out the door found that the customers were not happy. They were severely nose heavy and would dive under the snow in soft, deep, winter snow conditions. Here at RMS MX we worked with the 2017 spindle, and rear skid setup, to find that there is a setup that makes the Yeti light on the front but holds the ski in an aggressive manner that will carve hard when you need it. We also found that our setup could handle the hard crusty spring snow that the Yeti ski hates. With one quick adjustment of the forks in the tripple clamps on the day of the ride you now have a Yeti ski that is light on the shoulders and does not want to auto climb up a side hill. Then when the 18" of fresh comes the next day you reset the forks and have a ski the cuts hard in powder conditions with out front end wash.

I know that this set up information is vague, but that is the way it was intended. We have spent so much blood sweat and tears on developing our setup. We respectfully reserve it of our customers. If you are doing business with us you ave access to all of the knowledge we have developed. Buying a Yeti is like buying a race car. With the right tuning and set up it is unbelievable. With the wrong setup a 13 year old in a gocart could out drive you. We would like to earn your business by the dedication we have to the snow bike industry and by the time and effort we put into this sport.

shortstuff said:

How are you powering the gauges on the yz250?

Sent from my SCH-I545 using Tapatalk

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Great question. I forgot to cover that.

We are powering the EGT gauge with a small rechargeable 12v lithium battery from the remote control car world. It will power it up for days on end before recharge is needed. It is zipp tied to the upper fork behind the number plate.

M5- said:

How many hours do you have on the ESR 345 kit. What is the life expectancy of the kit running as a snow bike? Lastly does that motor need race fuel?

M5

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We went an entire season on the 345 with out a hour meter so I do not know, I would imagine it did at least 40 hours on the 345. I would say rings once a season. We are scheduled for a full tear down and inspection in the next month.

This one runs at 9-12K and is happy on 91 non eth.