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Are 4-Strokes Really Closing the Gap?

Reeb

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I had this massive post all written up and when I went to reply the webpage threw up an error and told me to reload. Lost the entire thing. I'm too dejected to even try to do it again. I spent way too much time on it the first time dammit.
 

LoudHandle

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When there is a 300 plus Horsepower 4 Stroke that weighs under 100#'s RTR.

I'll build a chassis for it! Until then I'll keep 2 Stroking! On a sub 400# sled.
 

LoudHandle

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A 100#'s?! Hope you mean the engine! Lol

Yes, 100#'s ready to run, if it needs to be boosted to get there then that weight would be included. As well as all the electrical needed to run.

The only engine in the running currently is the 3 cylinder Nissan that puts out about 400HP and a claimed 85# package. But there is limited information on that engine, guessing the 85# claim is without electrical, turbo, etc. although the photos indicate a very slim water jacket profile and a little Japanese guy is holding it without straining.
 
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BigFish BC

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Yes, 100#'s ready to run, if it needs to be boosted to get there then that weight would be included. As well as all the electrical needed to run.

The only engine in the running currently is the 3 cylinder Nissan that puts out about 400HP and a claimed 85# package. But there is limited information on that engine, guessing the 85# claim is without electrical, turbo, etc. although the photos indicate a very slim water jacket profile and a little Japanese guy is holding it without straining.

that motor didnt last long this year in the lemans did not hear what happened though but was out in the first couple hours.
 
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BigFish BC

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some of you guys are way to fixated on weight:rolleyes::deadhorse:it is important but the whole overall package is more important.i love the 4strokes & will keep riding them as long as they make me happy . iam glad yammi keeps making them better even if you 2 stroke guys dont think so. if you think your 2 strokes would be where they are without 4strokes,give your head a shake,yammi pushing 4strokes has made the 2s push even harder just to stay ahead.the gap has closed just not enough for some people but allot of you guys will never be happy no matter what yammi does.:face-icon-small-coo
 

nytro41

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NO, Weight will never be close....A non turbo 4stroke Yammi vs non turbo 2stroke Poo, Cat or XM not even close.

Wishful Thinking
DPG


this guy said this awhile ago but maybe someone already set him straight. but you do realize DPG that the R1 motor is a 4 stroke. and pushing 190 HP. the 4 strokes will push just as much. you cant spin a clutch at 16000 rpm. so gear it down. but the R1 motor pushes more HP then any of the snowmobile 2 strokes.

Just Sayin
 

cacsrx1

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this guy said this awhile ago but maybe someone already set him straight. but you do realize DPG that the R1 motor is a 4 stroke. and pushing 190 HP. the 4 strokes will push just as much. you cant spin a clutch at 16000 rpm. so gear it down. but the R1 motor pushes more HP then any of the snowmobile 2 strokes.

Just Sayin

And the CrossPlane R1 motor is WAY heavier than the currently used triple. It will also not survive in sustained high RPM situations encountered in the snowmobile world. It makes peak power of 180hp at 12700 rpm, it does not spin 16,000 rpms.
Just saying.
 
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stingray719

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I bought another Viper and am going to boost it so the 2014 M8 is for sale now. Thats what I think of the Viper after putting some real world miles on one.

So yeah for me the 4 stroke Yamaha is finally my first choice for a mountain sled.

DISCLAIMER - I may not ride like you so the opinion above is my own that I backed up with cash. The way you ride may not lend a 4 stroke to your way of life.
 

nytro41

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And the CrossPlane R1 motor is WAY heavier than the currently used triple. It will also not survive in sustained high RPM situations encountered in the snowmobile world. It makes peak power of 180hp at 12700 rpm, it does not spin 16,000 rpms.
Just saying.

sorry i didnt do some hardcore research on it. im saying its based off the R1 motor. yes the triples are lighter. what im saying is the 4 strokes can hit the power. just no one has turned them up except the race sleds yamaha currently runs. 4 stroke triples are 30 pounds heavier then a 2 cylinder 2 stroke motor. i have weighed them. thats just the engine though no other parts. so i would think you can get the 4 stroke sled within 50 pounds of a 2 stroke.

Just sayin
 

snowbikekits.com

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This coming season will be the 12th season of yamaha 4sttokes. The motors have not really changed a lot since then nor have their platforms. I have been and am a huge fan of everything yamaha but their snowmobiles have been a huge disappointment. New a.c. Chassis is nice but to me it's like having your parents do a school project for you and then turning it in as your own. Yamaha needs to step it up. I would rather have a 10 year old viper than a new 4 stroke. I want Yamaha to step it up and get back onto the game. Better lighter engines and a chassis that is their own. The SR Viper is a compromise and that's that.
 
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christopher

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This coming season will be the 12th season of yamaha 4sttokes. The motors have not really changed a lot since then nor have their platforms. I have been and am a huge fan of everything yamaha but their snowmobiles have been a huge disappointment. Yamaha needs to step it up. I want Yamaha to step it up and get back onto the game. Better lighter engines and a chassis that is their own.
I think everyone would agree with you on that.
 
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stingray719

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This coming season will be the 12th season of yamaha 4sttokes. The motors have not really changed a lot since then nor have their platforms. I have been and am a huge fan of everything yamaha but their snowmobiles have been a huge disappointment. New a.c. Chassis is nice but to me it's like having your parents do a school project for you and then turning it in as your own. Yamaha needs to step it up. I would rather have a 10 year old viper than a new 4 stroke. I want Yamaha to step it up and get back onto the game. Better lighter engines and a chassis that is their own. The B
Viper is a compromise and that's that.




And we disagree but that is good and healthy. If I had to ride my old Viper instead of my new one I would probably stay home most weeknds. The old Viper was miserable in the deep powder and sidehilled like crap. Lotta fun on the groomed roads though as was the RX1 (still have one).

So coming from somebody who has or has had both comparing the old Viper to the new Viper might as well be comparing the SS440 to the Nytro. My opinion of course...

And you probably missed my post from last year but Yamahas heyday was the SRX back in the 70's which came from thier partnership with SNO JET. Quick history lesson, Yamaha sold engines to SNO JET and the Thunderjet won everything to win in 1973, never done before or since. Next year production limits forced them out of racing and eventualy meant there demise. Big surprise Yamaha comes out with a thunderjet clone and the SRX is born. We could only hope that history is repeating itself with Cat/Yamaha venture

These look alike?

attachment.php


attachment.php


1977YamahaSRX.jpg thunderjet.jpg
 
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CatRpillar

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I don't care if Frito-Lay makes their chassis. If it works then who cares?:face-icon-small-ton

As for engine weight - Yamaha could make a motor that is much lighter but then we'd all complain when you have to change cranks, pistons, etc every two seasons - wait, I take that back, that's what Polaris and Doo do and people buy them!
 

off trail mike

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The thread continues......

Yep....New engine required....700-900cc turbo is the only option for high performance 4S IMO and Yami has lots of options there. The Nytro and Apex engines are old now and need a weight loss/perf. gain. Think all the bike manufacturers are heading in the turbo direction anyway, so it won't be a stretch.

BTW, I'd would like to know the difference between an 800 E-Tec with tuned pipe included and Nytro with header (assuming both need mufflers). I bet its relatively tight, and the Nytro isn't exactly a lightweight.

Chassis? You a Nytro chassis hater? In stock trim, I couldn't agree more but with 3+" forward A-arms (I use Skinz @ 4.5") handling took a huge step in the right direction. The only thing I thought missing was reduced steering effort, and the Skinz front end made this problem worse IMO.

It was said earlier in the thread, Yami are capable and should use their AC joint venture and possibly even aftermarket to improve the breed. They could have used a Skinz type seat and a "Trailtank" under seat fuel tank to lower Nytro CG and it would have been a real improvement. The Viper is a step too, but as it is now a 5 year old chassis, it's a bit unclear to me how valuable it will be in the mountain segment. Perhaps new ones are close on the horizon!

Personally, I run a 2014 154 XM, which is awesome and a rather modified 153 NA Nytro which I love equally as well. The XM showed me how important steering effort is on a mountain sled and how it translates into an all day flickable, rideable sled. Because the Nytro has a heavier front, it won't go side to side as fast, but there is no excuse for "heavy steering". That's purely an error, where the machine was designed with trail riding in mind first and little consideration for mountain riders.

So in my small effort to "improve the breed", I am converting my Nytro to a 3+ forward A-Arm, 37" stance direct steer over the summer. Can't wait to see the overall effect, but I'm betting I can close in on the XM's feel, and if I can do that with my old Nytro 4S, it will both eliminate my last "real" beef with the Nytro....and allow me to finally see what a "real" 4S mountain sled could potentially feel like up against my very fun 2S.

Don't think I'm alone here either. Lots of guys ignore the forum noise and are already building 4S's to go everywhere they want. My hope is that everyone gets a chance to experience what they already know so the manufacturers can finally catch up to the custom builders and put these sleds into the hands of many.

Always good to dream!

OTM
 
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stingray719

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The thread continues......

Yep....New engine required....700-900cc turbo is the only option for high performance 4S IMO and Yami has lots of options there. The Nytro and Apex engines are old now and need a weight loss/perf. gain. Think all the bike manufacturers are heading in the turbo direction anyway, so it won't be a stretch.

BTW, I'd would like to know the difference between an 800 E-Tec with tuned pipe included and Nytro with header (assuming both need mufflers). I bet its relatively tight, and the Nytro isn't exactly a lightweight.

Chassis? You a Nytro chassis hater? In stock trim, I couldn't agree more but with 3+" forward A-arms (I use Skinz @ 4.5") handling took a huge step in the right direction. The only thing I thought missing was reduced steering effort, and the Skinz front end made this problem worse IMO.

It was said earlier in the thread, Yami are capable and should use their AC joint venture and possibly even aftermarket to improve the breed. They could have used a Skinz type seat and a "Trailtank" under seat fuel tank to lower Nytro CG and it would have been a real improvement. The Viper is a step too, but as it is now a 5 year old chassis, it's a bit unclear to me how valuable it will be in the mountain segment. Perhaps new ones are close on the horizon!

Personally, I run a 2014 154 XM, which is awesome and a rather modified 153 NA Nytro which I love equally as well. The XM showed me how important steering effort is on a mountain sled and how it translates into an all day flickable, rideable sled. Because the Nytro has a heavier front, it won't go side to side as fast, but there is no excuse for "heavy steering". That's purely an error, where the machine was designed with trail riding in mind first and little consideration for mountain riders.

So in my small effort to "improve the breed", I am converting my Nytro to a 3+ forward A-Arm, 37" stance direct steer over the summer. Can't wait to see the overall effect, but I'm betting I can close in on the XM's feel, and if I can do that with my old Nytro 4S, it will both eliminate my last "real" beef with the Nytro....and allow me to finally see what a "real" 4S mountain sled could potentially feel like up against my very fun 2S.

Don't think I'm alone here either. Lots of guys ignore the forum noise and are already building 4S's to go everywhere they want. My hope is that everyone gets a chance to experience what they already know so the manufacturers can finally catch up to the custom builders and put these sleds into the hands of many.

Always good to dream!

OTM


Mike, I had two Nytros one for me and one for girlfriend. Mine was 280hp supercharged and hers was N/A cut down to 560 pounds wet and 36 inch front end 2 inch forward with Timbersled rear skid and fox floats all the way around. YES it was miles better than stock but just as far from the 2014 Viper or the 2014 M8.

Ride a 2014 (not 2012 or 2013) M8 or a correctly setup Mountain Viper.....you have a pleasant surprise coming!
 

off trail mike

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Yeah, I missed my opportunity to ride the Viper MTX this spring on account of work and was pretty bummed about it. I have driven a 13 M, but not a 14 and heard the same thing that they are miles better. I think I'll keep the Nytro for one more year, but totally agreed.... it is not likely to age well against the newer iron.

I am curious what you thought was the big difference between your Nytro's and the new Viper MTX? Is it general feel or something more specific?

I found the biggest changes on my Nytro that narrowed the gap to the competition were the Skinz front suspension, Timbersled skid, More HP and the weight loss in that order.

To your point though...can't wait to compare the new Viper MTX to the old beast this winter.

OTM
 
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stingray719

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Yeah, I missed my opportunity to ride the Viper MTX this spring on account of work and was pretty bummed about it. I have driven a 13 M, but not a 14 and heard the same thing that they are miles better. I think I'll keep the Nytro for one more year, but totally agreed.... it is not likely to age well against the newer iron.

I am curious what you thought was the big difference between your Nytro's and the new Viper MTX? Is it general feel or something more specific?

I found the biggest changes on my Nytro that narrowed the gap to the competition were the Skinz front suspension, Timbersled skid, More HP and the weight loss in that order.

To your point though...can't wait to compare the new Viper MTX to the old beast this winter.

OTM


The short version is ease of ride. The first day I rolled the M8 on me 3 or 4 times as I grabbed a handful of handlebars and gave a big yank thinking I was still on a Nytro. Still kinda funny laying there in the snow laughing as the girlfriend pulls up worried because I didn't get up right away. Now on either the M8 or converted MTX Viper I can lean left steer right and carry the right front ski as far as I want and never stand up. I rarely stand any more in fact, its that easy to ride. We ride 3 times longer per day than we did on Nytros.

Viper ended up handling just like the M8 as soon as I moved the front skid shock lower mounting point forward similar to the M8. But I suspect that is already taken care of on the 2015 MTX and if not I can send ya specs on where to drill new hole.

I CAN'T WAIT FOR SNOW!!!!!!

Oh, I heard a rumor that Christopher is giving demo rides on his new special edition turbo Viper as soon as it snows.....anybody else hear that?
 
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