2018 Super Hero Builds 17’ KTM 350SX and 18’ Yamaha YZ450F w/ Yeti 129SS

tillbuilt · Feb 2, 2019

2018 Super Hero Builds 17’ KTM 350SX and 18’ Yamaha YZ450F w/ Yeti 129SS

If you like our builds and get something out of it. Please offer us your business. We love giving great customer service to our customers. Rocky Mountain Snow MX 720-263-7533

We are a Yeti and Camso dealer and offer most of the snow bike accessories that you see in these post. We personally test every product we sell on our shop bikes so you can rest assured that what you are buying from us, is what truly works on a snow bike. This process will save you money in the long run by not having to replace a product you purchased for your snow bike and it did not work as you intended. We ship kits and accesories all over the US to our customers. We do not do internet sales from our website, because we strive to offer a high level of customer service and consultation so you get the right products the first time. We love talking to our customers, so give us a call and we can help you with your builds. Toby

This is the year Yeti reveals the 129SS (Super Sport)!!!!!!!!!

Wayback in March when Yeti snow check was released and it was confirmed that there would be a 10.5" wide Yeti 129 we really wondered what was to come? What came was a game changer!!!! The narrow 129SS (Super Sport) was equipped with the Camso Snow Bike track that is very similar to the Camso DTS 129 track that we had ridden in deep powder and could not believe how well the track did in DEEP powder situations. The other thing that Yeti did was narrow the rails from industry standard 8.75" to 5.5" rail spacing. This gives ample track width outside of the windows and it also gave a very narrow feeling to the system. This new track rolls more like a tire then anything else we’ve ever ridden!! With 5.5" rail spacing it really gives you the ability to lean through corners with out a hard edge to overcome. The 129SS in the 10.5" wide gives the same footprint as a 120 that’s 12.5" wide. So having the nimbleness of a narrow track, and the flotation of a 120 is the perfect combination for most riders 200 pounds and below. With the 20 to 45 pounds of weight savings that the Yeti 129SS offers compared to other manufactures. It opens up the ability for a rider 200 pounds and below to be on a very nimble kit. Where as traditional 120's of other manufacturers don’t do well with riders over 180 pounds.

We decided that we were going to build multiple 129SS bikes this season. First on the list was Flash, which is a 2017 KTM 350SX with a 2018 Yeti 129SS, then Wonder Woman, a 2017 Yamaha YZ250, she moved from a 2017 Yeti 120, to a 2018 Yeti 129SS. Next was to build the Blue Ranger. A 2018 Yamaha YZ450F with a 2018 Yeti 129SS, and last was Ferrari, a 2017 Yamaha YZ450F all out race bike making huge naturally aspirated power coupled to a 2018 Yeti 129SS custom snow check with every option. Our goal is to see what bike combinations work well and have advantages with the 129SS.

tillbuilt · Feb 2, 2019

2018 Super Hero Builds 17’ KTM 350SX and 18’ Yamaha YZ450F w/ Yeti 129SS

The first build off of the lift was the Flash, a 2017 KTM 350SX with a 2018 Yeti 129SS. This build was focused on being a very light weight, four stroke that will pull hard and be two-stroke kind of mountain fun. We wanted a tree riding machine that you "ride it like you stole it" and come out the other side, shaking from adrenaline, and branches sticking out of you helmet. With that in mind, the build began.

The PST engine jacket keeps the heat in, along with the Acerbis skid plate to seal at the bottom. The goal is for the thermostat to bring the temps up, and the engine jacket to keep them in. This particular set up works well, but with the KTM exhaust exiting through the front of the frame it has to have a large opening in the jacket. Unfortunately in fender deep snow, even with all of the heat add-ons, we still saw temperatures down around 100°.

Split Designs came on this year to do our graphics and design work. As you can see they did a great job!!!! The beautiful orange anodized colors that we got with the Yeti snow check really set off this bike.

We were intent on keeping this bike light weight so we retained the AER air forks and built them to withstand the cold temperatures. By the end of the season, we can say that "we went the entire season without a AER fork failure".

The Yeti air intake was flawless all season. Using the Yeti fuel injected intake, along with cutting the airbox completely out, kept us breathing well all season.

We also changed the battery box to a EXE unit to accommodate the larger Earth X lipO4 battery we like to use. This battery works at very cold temperature and starts the bike with ease. A good battery is crutital on an electric start only bike.

The electric Trail Tech fan kit keeps us rocking in the spring time if the bike starts to get too hot.

We wanted all out performance for this 350 on the snow so we added Raze Motorsports, thermostat, heated bars, ECM, and NOS.

The Raze ECM did keep the bike from over fueling and washing gas by the rings, so we did not have large amounts of gas in our oil. We also set the rev limiter at 13,000 RPM. This gave us that little extra reach that we wanted in the power band.

The Yoshimura exhaust gave us a nice horsepower gain, and the P3 universal heat shields kept it from burning our awesome Klim gear.

We added Bullet Proof designs one piece aluminum radiator guards to keep the trees out of the radiators, and the ice off the front. The stock plastic fins build so much ice and do not protect from a tree stab. The billet aluminum guards transfer heat from the radiators to the guard and help melt the snow and ice off, decreasing weight.

We also installed ProMoto Billet foot pegs, handlebar risers, bark busters, and fit1 top clamp to help us control this angry beast. In addition, we added the Cyclops Adventure headlight and Trail Tech TTO temperature gage to keep an eye on engine tips.

The Seat Concepts seat was comfy all season, and truly helps steer the bike from your backside.

After the build, we hung it from the scale. We were excited to hit the snow!!! This is the lightest four stroke that has ever come out of our shop.

Off we go to test our build. We will give an end of season review of all products and bike later in this post.

byeatts · Feb 2, 2019

tillbuilt said:
The first build off of the lift was the Flash, a 2017 KTM 350SX with a 2018 Yeti 129SS. This build was focused on being a very light weight, four stroke that will pull hard and be two-stroke kind of mountain fun. We wanted a tree riding machine that you "ride it like you stole it" and come out the other side, shaking from adrenaline, and branches sticking out of you helmet. With that in mind, the build began.

The PST engine jacket keeps the heat in, along with the Acerbis skid plate to seal at the bottom. The goal is for the thermostat to bring the temps up, and the engine jacket to keep them in. This particular set up works well, but with the KTM exhaust exiting through the front of the frame it has to have a large opening in the jacket. Unfortunately in fender deep snow, even with all of the heat add-ons, we still saw temperatures down around 100°.

Split Designs came on this year to do our graphics and design work. As you can see they did a great job!!!! The beautiful orange anodized colors that we got with the Yeti snow check really set off this bike.

We were intent on keeping this bike light weight so we retained the AER air forks and built them to withstand the cold temperatures. By the end of the season, we can say that "we went the entire season without a AER fork failure".

The Yeti air intake was flawless all season. Using the Yeti fuel injected intake, along with cutting the airbox completely out, kept us breathing well all season.

We also changed the battery box to a EXE unit to accommodate the larger Earth X lipO4 battery we like to use. This battery works at very cold temperature and starts the bike with ease. A good battery is crutital on an electric start only bike.

The electric Trail Tech fan kit keeps us rocking in the spring time if the bike starts to get too hot.

We wanted all out performance for this 350 on the snow so we added Raze Motorsports, thermostat, heated bars, ECM, and NOS.

The Raze ECM did keep the bike from over fueling and washing gas by the rings, so we did not have large amounts of gas in our oil. We also set the rev limiter at 13,000 RPM. This gave us that little extra reach that we wanted in the power band.

The Yoshimura exhaust gave us a nice horsepower gain, and the P3 universal heat shields kept it from burning our awesome Klim gear.

We added Bullet Proof designs one piece aluminum radiator guards to keep the trees out of the radiators, and the ice off the front. The stock plastic fins build so much ice and do not protect from a tree stab. The billet aluminum guards transfer heat from the radiators to the guard and help melt the snow and ice off, decreasing weight.

We also installed ProMoto Billet foot pegs, handlebar risers, bark busters, and fit1 top clamp to help us control this angry beast. In addition, we added the Cyclops Adventure headlight and Trail Tech TTO temperature gage to keep an eye on engine tips.

The Seat Concepts seat was comfy all season, and truly helps steer the bike from your backside.

After the build, we hung it from the scale. We were excited to hit the snow!!! This is the lightest four stroke that has ever come out of our shop.

Off we go to test our build. We will give an end of season review of all products and bike later in this post.

Everyone thinks they can build a bike up . These guys are doing it correctly for trouble free riding,,,

lawnboy · Feb 2, 2019

Thanks for sharing your builds!! I highly recommend Toby. I was having trouble fitting a Yeti spindle to one of my bikes. I reached out to Toby and he helped me to get it figured out. Part was at my door few days later. Thanks Toby

Chadx · Feb 3, 2019

Toby,
Love your builds, comparisons and product research. Super valuable and always much appreciated.

Byeatts,
You may want to edit your post to delete the "quote" portion. Quoting superlong posts in forums just has everyone scrolling past the big long quoted portion. Thanks!

tillbuilt · Feb 5, 2019

Flash is now ready to hit the snow. It’s first ride out was for family time. We all went to Grand Lake, which gave me a good opportunity to get out Flash and ride it for the first time. It was definitely a challenging day.

The Raze NOS system that was installed on this bike left a lot to be desired. When the NOS hit comes on is noticeable but not impressive, and the way that the ECM ran, I was worried that I might not make it out of the woods. The drivability of this system left a lot to be desired. Do remember that this bike does have a Yeti intake and Yoshimura exhaust. After lots of troubleshooting, and working with Raze. They told me that they would be in town for the X games, and to meet them on the mountain. So we loaded up and spent four hours with Raze on the side of the mountain tuning and trying to get this bike to run right. After an ECM change and much technical assistance from Raze in person, this bike finally runs well. Operating in position 1, running no NOS. It still has some negative driveability issues, and does not start well, but runs well once warm. In position 2, NOS activated, it does provide a small NOS hit. It is just enough to pull you through a tight spot but not oh my gosh impressive. After all the work that was done, it still has a very hard time starting cold and we feel that because Raze is tuning to maximum horsepower, that any change from initial design, such as intake, exhaust, cams, and so on gets their tune out of wack. We feel that their system is very difficult to sell to the end-user, due to the fact that most customers have a verity of aftermarket parts on their bikes. The rideability warm is very close on this bike now, and it runs quite well but we don’t feel that the amount of added benefit of a small hit of NOS is worth the 13 pounds of weight that you have to tote around all day.

On the way back to the trailer the Yeti belt walked off and went through the cover. We had never seen this before, but the good news was Yeti had already started seeing reports of this happening on other 129SS. It turns out there was variation in the carbon cutting jig ONLY for the 129SS. Yeti immediately designed a floating upper jack shaft bearing service bulletin that went out to all dealers to fix and align the jack shaft to the driveshaft. They were very prompt in their service bulletin release and took great care of all of their customers. Most of the world barely even knows that this was happening because of their prompt response. Once this service bulletin is completed on the 129SS there is no more belt problems. This upper floating bearing is now standard on all Yeti systems.

Sent from my iPhone using Tapatalk

tillbuilt · Feb 6, 2019

2018 Super Hero Builds 17’ KTM 350SX and 18’ Yamaha YZ450F w/ Yeti 129SS

The second ride out was exactly what we were looking for with this build!!!! We got to go into some tight trees with a good running bike and started to rail. Our goal was to have a hair on fire, face bleeding, branch is sticking out of your helmet kind a ride, and that’s what we got!!!! The first time I was able to get this thing on a side hill, and find the rev limiter was a smiles for days kind of experience!!!! When I was rocking through the super-tight trees, I could not believe that we had built exactly what we were after. We could totally feel the lightness of this bike, and when the 350 gets into its power about 8000 RPM and brings that power all the way to the 13,000 RPM rev limiter you have a wide range of throttle whacking, extreme fun in the tight trees. Then to add to it, we were so impressed with the deep powder performance of this new track. The Camso snow bike track that came on the 129SS was a dream come true. This a little narrow track paddled through fresh deep snow like the wide tracks of the past, but it gave extreme nimbleness to the bike. We have never felt something like this. It rode so much more like a tire than anything we have ever been on. This 129SS even made the trail a fun place to be. I found myself blasting down the trail at 50mph., pushing it hard into the corners, with all of the confidence in the world.

So after a full season with the Flash, we have come to the realization that we love this kind of set up. It is the perfect mix of two-stroke kind of spring riding, with deep day performance. Our typical two-stroke builds are awesome in the set up spring snow, but on the deeper days need a little bit more. The Flash on the other hand is unbelievable in the spring time riding, and will hang on the deep days also. We love how it performs in all conditions. This is definitely our choice if we only could build one bike.

Now don’t read into this as this as this is the one bike solution for everyone. You have to remember that we are 180 to 190 pound riders with lots of experience on the snow. So with our weight, combined with our skills, this bike really works. I have many riders try this bike throughout the season. The ones that were very aggressive, and good riders, absolutely loved the Flash. The ones that never brought the bike above 9000 RPM hated it. So it all comes down to rider style and ability. The one rider that surprised me the most was an inexperienced woman rider. She was brand new and felt that the flash was the most nimble and easiest to ride out of the entire fleet. Now she wasn’t powder riding, and it was hard spring snow, but she did feel the Flash was the best because if it’s lightweight in nimbleness. It was very easy for her to ride.

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2018 Super Hero Builds 17’ KTM 350SX and 18’ Yamaha YZ450F w/ Yeti 129SS

tillbuilt

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tillbuilt

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byeatts

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lawnboy

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Chadx

♫ In the pow again. Just can't wait to get in..

tillbuilt

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tillbuilt

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