Top speed is 70mph

[Vipermtxsweden]

I drove my Viper mtx153 with MCX 190 for the first time yesterday.
but I regret to say that it goes a little harder than the standard Summit 800 and im still load 6 bar.
The Swedish version comes with a 66 millimeter track 24/50 gearing mayby that is the issue
ran a Nytro last year will probably buy it back if i cant any speed in this sled
Any ideas what to do or buy to get some speed or power in the new viper

 

[stingray719]

I drove my Viper mtx153 with MCX 190 for the first time yesterday.
but I regret to say that it goes a little harder than the standard Summit 800 and im still load 6 bar.
The Swedish version comes with a 66 millimeter track 24/50 gearing mayby that is the issue
ran a Nytro last year will probably buy it back if i cant any speed in this sled
Any ideas what to do or buy to get some speed or power in the new viper

Probably in your clutch setup. My Viper with air box mod and can will outrun an 800 Ski Doo so your turbo Viper should be MUCH faster. Call MCX for clutch information or look here - http://www.ty4stroke.com/threads/clutching-on-the-cheap.129971/
Also if you are running the original 8JP belt that might be your issues look here - http://www.ty4stroke.com/threads/losing-rpm-and-not-holding-normal-top-speed.126678/

 

[Simoneau+]

Hi, i got the same exact sled as you 2015 mtx 153 and i have seen easily 80-82 mph on the speedo on short straigh not held it 5 min to get there.
Maybe you dont got the low altitude clutch kit ?
I live in Quebec not far from you and when my dealer give me my sled it was clutched for high altitude (i will it the limiter about 300 time in 5min).
Chek if you got the stock 8bu with no rivet (two empty hole) mine came like that from factory, now i run the yamaha low alt. kit (2 rivet/30*sec. spring wrap) and its way better still not perfect but im waiting on my turbo so i dont want to mess with clutching right now.
Maybe it will help you ...

 

[Rev-it]

84 mph on stock gearing 4psi boost. Went the opposite and geared it up as much as I could it seems like it gets there quicker. 65-70 mph it starts vibrating( track ballooning)

 

[Vipermtxsweden]

I have the mcx weights and artic Green secondary spring an shockwave in the bottom at 43 degre angle
My buddy has the same setup accept epi purple secondary spring My sled is hitting the rev about 8900 and stil doesent lift the skies from the snow

 

[Boostd]

The cat green spring is s bit much for the 180 kits. I would recommend the white/white spring from yamaha at 6-2 at the most.
I don't run the green springs until 240hp and up with more helix.

 

[Vipermtxsweden]

Im going to buy ww spring tomorrow and 8dn belt and try it on saturday
What weights is all turboguys riding stm or heelclicker?
Was very happy with stm on My nytro 270 last year

 

[Boostd]

Stock weights work great, no need to change.
Again, stm weights are awesome and very tuneble but not needed in the low boost kits. I don't start using those until the 240 and higher kits.

 

[viperdudese]

Im going to buy ww spring tomorrow and 8dn belt and try it on saturday
What weights is all turboguys riding stm or heelclicker?
Was very happy with stm on My nytro 270 last year

I allso drive a mtx 153 se, but i have mine stock in the secundary and just changed the the helix one hole up so the spring get stiffer.
And in the premiereclutch i ride with stock spring and supertip x55g weights with 14-5-0, and my skies are lifting! hitting the rev on hard snow. Got mine up to 90mph (144km/h) so i'm going to put in 21/49 gearing instead of the stock 24/50 that the european vipers came with.
And after that, i think i will go back to stock weights, the supertip are a little to rough in the beginning, the sled starts to pull at 4050Rpm than it falls to 3400Rpm....

 

[Rev-it]

Got the new track in my hand so it's time to start cutting the one on the sled. Have to find something to cut notches in it after. Ordered the 160lb spring for the skid shock. Got a 8dn belt just in case and upsp says my OTS belt adjuster is cleared customs. -32 and the coffee is tasting to good to go outside and start the heater, the sled and put the two in the same shed together.

 

[Rev-it]

Ok well cut the track down to 1.75 and took it out today the lake was rough and in behind a island i was seeing 94 on the speedo on the trail i just made 4 passes and 95-97.
got to town and there was a short stretch of packed sled trails with minimal drifts spanked her from about 45 and she was at 95 fast and climbed to 98 then I ran out of bay.
Tach holding at 8600RPM I dont have and springs or weights at home but I did tighten up the secondary spring one notch because when backing off fast it doesnt shift all the way out so when I go to leave it jumps till its moved 20'
Dont know how close the dream-o-meter is on the viper, cant find my gps from hunting season.

 

[viperdudese]

Now i have done some adjustments on the clutching !
I removed the Supertip X55 weights and changed the profil a little on the stock weights, i drilled out the outer rivets and put in a M6 bolt and nuts so the weights is still 79grams. Now the Speed follows the RPM linear put i lost about 5km/h. But now the sled pulls my arms lika a horsekick in the nuts!
So for a 190hp Viper the Supertips are to much i think... still waiting on the 21/49 gearing!

 

[stingray719]

Tested mine today, sled is geared to 85mph no turbo. Pulls like a freight train to 70 tapers off a little and falls off fast at 80mph, didn't go over 82 before I shut down. I am VERY pleased with this Viper.

 

[tapex_07]

I have rented a number of 13+ M8's, 153 and 162 2.6, and none of them go much more than 70 even on long long pulls..

 

[stingray719]

I have rented a number of 13+ M8's, 153 and 162 2.6, and none of them go much more than 70 even on long long pulls..

Yep, my 2014 M8 didn't want to go much over 70.