2019 Super Hero Builds 19' Honda CRF450R w/ 2020 Yeti 129 FR (FBS) 18’ Yamaha YZ450F w/ 2020 Yeti 137 MTN (FBS)

[tillbuilt]

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

We are a Yeti 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 systems 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

Here is the rundown of what is in store for this year's builds:

Blue Ranger 2018 Yamaha YZ450F built in 2018, but gets the new 137 Yeti 2020 FBS track system:








Red Ranger 2019 Honda CRF450R with a 129 Yeti 2020 FBS track system:






This season was a blast!!!!!! We got to put a red bike in our shop fleet for the first time and truly see how it stack's up.

 

[n16ht5]

looks great. the new yetis ride so nice. How has that ski scratcher been working?

 

[cek]

Toby has earned my business. he put together a yeti 120 for my sons CRF150R. Just started putting it together with my son and am absolutely stoked with how it’s coming together. Hopefully finish it up this weekend. Thanks again Toby I’ll be talking to you soon.
Anyone who is on the fence should give him a call.

 

[Chadx]

As with all of your build and ride reports, Toby, looking forward to these. Always great comparison and love how much detail you go into.

 

[tillbuilt]

looks great. the new yetis ride so nice. How has that ski scratcher been working?

This ice scratcher is a new product we are testing this season. I will have more info for you as the season goes on. Good spot BTW!!!!

 

[tillbuilt]

As some of you may know I had a bike fall over on me in the shop about this time last season and broke my leg. So the Red Ranger build did not get to the snow until March. This is also the same time that we got our early release 2020 Yeti dealer demo kits. This is why it has a 2020 and not a 2019.

Back in February I was asked by Yeti to come down to their back country testing area with two of my customers to ride and give our first impressions of the new 2020 Yeti systems. This new system has carried the nickname of Fat Boy Slim ( FBS ). It is a wide track on narrow rails.

Here is the video from that experience.




Our first ride in February was a 2020 Yeti 137 MT on a Husky 501 and we could not believe how this thing handled. The huge 137 FBS felt like you were riding a 129. We were so impressed with how this new FBS design handled. On the hard packed trails it rolled more like a tire than anything we had ever been on, and in the back country its float was amazing!!! This Camso\ Yeti snow bike track paddles the deep powder better than any other track we have ever tried. Even in the crusty spring snow it did not fold over. It just grabs and claws its way to the top. The one down side to this new FBS design is that you have to watch out for those frozen trail rides in. The added track outside the rails does not let snow in to lubricate the hyfax well. We feel you need to run the bogie wheels and drag your feet to slow down hyfax wear. This is why we are working on a scratchier also. We did burn up hyfax on a early morning ride in when we were not dragging our feet.




Once we got the 129 FR on the Red Ranger and the 137 MT on the Blue Ranger it was on!!!!! We were able to put 26 hours on the Red Ranger before the end of the season and loved every minute. The combo of the the 2019 Honda and the 129 FR was the best bike we have built to date. Everyone that rode this bike was super impressed!!!!


The Blue Ranger had a short life with the 2020 137 MT. Its first ride out this season with 64hrs. on the clock it had a big end rod failure in the motor, so you all know what that means in the RMS shop. Time to upgrade, and that does not happen fast. The motor went out and did not get back in time for the season. The good news is, the Blue Ranger went from making 42hp. at the rear wheel to 65hp. at the rear wheel. We are now all set for the 2020 season with a big track and big power.

 

[Ktm300]

As some of you may know I had a bike fall over on me in the shop about this time last season and broke my leg. So the Red Ranger build did not get to the snow until March. This is also the same time that we got our early release 2020 Yeti dealer demo kits. This is why it has a 2020 and not a 2019.

Back in February I was asked by Yeti to come down to their back country testing area with two of my customers to ride and give our first impressions of the new 2020 Yeti systems. This new system has carried the nickname of Fat Boy Slim ( FBS ). It is a wide track on narrow rails.

Here is the video from that experience.




Our first ride in February was a 2020 Yeti 137 MT on a Husky 501 and we could not believe how this thing handled. The huge 137 FBS felt like you were riding a 129. We were so impressed with how this new FBS design handled. On the hard packed trails it rolled more like a tire than anything we had ever been on, and in the back country its float was amazing!!! This Camso\ Yeti snow bike track paddles the deep powder better than any other track we have ever tried. Even in the crusty spring snow it did not fold over. It just grabs and claws its way to the top. The one down side to this new FBS design is that you have to watch out for those frozen trail rides in. The added track outside the rails does not let snow in to lubricate the hyfax well. We feel you need to run the bogie wheels and drag your feet to slow down hyfax wear. This is why we are working on a scratchier also. We did burn up hyfax on a early morning ride in when we were not dragging our feet.


View attachment 335128

Once we got the 129 FR on the Red Ranger and the 137 MT on the Blue Ranger it was on!!!!! We were able to put 26 hours on the Red Ranger before the end of the season and loved every minuet. The combo of the the 2019 Honda and the 129 FR was the best bike we have built to date. Everyone that rode this bike was super impressed!!!!


The Blue Ranger had a short life with the 2020 137 MT. Its first ride out this season with 64hrs. on the clock it had a big end rod failure in the motor, so you all know what that means in the RMS shop. Time to upgrade, and that does not happen fast. The motor went out and did not get back in time for the season. The good news is, the Blue Ranger went from making 42hp. at the rear wheel to 65hp. at the rear wheel. We are now all set for the 2020 season with a big track and big power.



View attachment 335125
View attachment 335126

Was the YZ all stock when it let go ? The reason I ask is because I’ve heard of stock YZ’s getting close to 100hrs on the stock top end without much fuss. I was hoping my 2018YZ would do the same. (I’ve got 54hrs now)

Also, would you mind sharing your recipe for the increased Hp ? When it does come time to rebuild my bike, I’d like to bump up the power when it’s apart. Assuming you strive for reliability over all else, I’d like to duplicate your setup.

 

[tillbuilt]

Yes the YZ was all stock when it let go. Yes, earlier YZ's went huge hours. It seems the 18' and maybe the 19's are having issues.

Yes I want reliability, but you can not make this kind of power reliable. Once you step over the 10hp. Line in the sand you can not use the word reliable in your sentence anymore. There is over $7K in this power build and I will be feeling good if it goes 50 hours before it comes apart. This is the world of big power Motorsports. You can not have your cake and eat it too.

 

[M5-]

I find it odd that the big end went out. The YZ uses the same bearing and rod all the way back to 2010 in the YZ450. The cranks are slightly different but fundamentally they haven't changed the formula. Did you have other issues before the failure? I've seen the balance shaft bearings fail but they make metal before they kill the motor usually.

 

[dooman92]

Toby, what oil was in that engine that lost the big end rod bearing? While lugging, or an engine with boost that bearing experiences the greatest psi load in the engine. Oil film strength is critical in that bearing. I believe Ktm went to the plain bearing, that distributes that load over a much larger surface area lowering psi load, for that reason.
We started the season with two new 450fx's three years ago. One with rotella 5/40 and one with Mobil 1 0/40. Road together most of the first season. At about 80-90 hrs the one running rotella t-6 lost the big end rod bearing (locked up requiring new crank). It was lugged more than the other. I rebuilt the one with mobil1 at about 200 hrs the internals were in very good condition. The crank showed no sign of any wear and was not replaced. The testing I have read indicates the film strength of the Mobil 1 0/40 is nearly double the Rotella. It would be nice to know if there is any correlation between failures and oil types.

 

[M5-]

Without straying too much off topic here, the FX is a different animal than the F being that the FX has a heavier flywheel plus its geared different. This tends to make the engine want to keep spinning longer, good for enduro bad for MX, after the throttle is released as well the FX is not able to hold 3rd in all cases, gearing differences, hence the lugging in 3rd or revving the pi$$ out of it in second, scenario. All the cracked pistons we have had have been on FX's so we are wondering if it has to do with the increased internal inertia of the rotating assembly and its desire to keep spinning. The F is on then its off no glide. So long story short it could be related to oil because to me its weird for an F to drop a rod bearing I could see it on an FX. I've been running T6 for years and I have blown up some motors so who knows. One side note, I was told the 0w40 T6 is NOT a JASO spec oil but the 5w40 is, I've never checked for myself

 

[dooman92]

Yeah, interesting. The additional lugging the fx is exposed to may explain load failures of crank and Pistons. Lugging increases load on piston and crank. If inclined to detonate it will most often happen while lugging. I have not seen any 0w-40 rotella in the states so uncertain about rating. But, the 5w-40 rotella we ran was jaso ma certified. I've been running 0w-40 mobile 1 euro formula for three years in a yami and a ktm. It is not jaso ma certified. I've had both apart including checking cranks. The yami had 200 hrs and was virtually unworn. Ring end gap was about .001 difference new to one with 200 hrs. The ktm was even better. It had about 80 hrs. The clutches in both appear unworn and do not slip that I can tell.

 

[dooman92]

M5, maybe you have seen this blog, if not it is an interesting read. 540ratblog.wordpress.com
It is an oil test blog. As a 50 yr grease monkey, fully certified auto tech in 1976, I found little to disagree with the author of the blog. Great info in my mind.

 

[tillbuilt]

Yes, I find it odd also. You are correct about the parts being the same. The crank is different, and Bundy Built has seen some of these failures and mostly in snowbike application. He does not know if it is a heat problem or a lubrication issue with the new crank and case half's, but the big end of the rod is walking over into the side of the crank at time of failure.

This motor was ran hard with me in the saddle, bouncing off the rev limiter at every opportunity. This was a Rotella T6 5w 40 motor, just like every Yamaha I have ever owned.

I find it odd that the big end went out. The YZ uses the same bearing and rod all the way back to 2010 in the YZ450. The cranks are slightly different but fundamentally they haven't changed the formula. Did you have other issues before the failure? I've seen the balance shaft bearings fail but they make metal before they kill the motor usually.

 

[M5-]

I'd kind of forgotten about this but one of the FX's where the piston cracked also had a bad main bearing. The inner race lost its plating, it didn't fail but it was just a matter of time. When your YZ let I'm assuming there was no trace of metal in previous oil changes?

 

[Ktm300]

One thing I’m curious as well, you had mentioned that the Honda with the free ride setup was one of the best builds you’ve done, does that mean that the Honda runs way stronger then the Yamaha stock for stock as a Snowbike ? I’m not looking to do a bunch of performance mods, but I’d like the hardest running stock bike. I thought my setup was good, but maybe it could be better with a different colour ? I don’t get the chance to ride other brands of bikes set up as snowbikes often unfortunately.

 

[dooman92]

I'd kind of forgotten about this but one of the FX's where the piston cracked also had a bad main bearing. The inner race lost its plating, it didn't fail but it was just a matter of time. When your YZ let I'm assuming there was no trace of metal in previous oil changes?

As for our crank failure on the fx, correct, no metal prior to failure. The crank locked up tight and slid the track. It got hot, I believe because the pressures exceeded the film strength of the oil resulting in metal to metal contact in that bearing.

I saw the same failure in a Yamaha 340 snowmobile engine that I did complete rebuild on this spring. It lost the oil line to the right side of crankcase starving that side of oil. Slight scoring of cylinder otherwise only failure in engine was the big end of the rod.

The way most ride the snowbikes, from lugging to bouncing off the rev limiter, put extreme pressure on that bearing requiring an oil with high film strength to survive. M5, I think your spot on with the comment about the 2-3 gap on the fx. One second your bouncing off the rev limiter then can't hold third and drop into a hard lug. That's hard on piston and crank rod bearing.

 

[byeatts]

Mobile One 0-40 work ok with wet clucth?

 

[Chadx]

Mobile One 0-40 work ok with wet clucth?

It's the grey cap/label Mobil 1 0w-40 diesel "european car formula" oil. Though it's not rated as wetclutch safe, it works well with wetclutches. It is not "enegy conserving" like the majority of the Mobil 1 automobile oil so none of the additives that cause wetclutch issues.

 

[byeatts]

Thats for gas engines not diesel?