So Ski-doo has a sub 500 4 stroke with 130HP stock??

[Veedy]

Seems there would be a bunch more inherent reliability in a 130 HP 4 stroke doing it under 8000 RPM than one doing it at 10,000 + !!!

Good Luck

When an engine is engineered for 10k rpm, It will be just as reliable as a motor designed for 8600 rpm, those are the facts. This aint no Briggs 'n Stratton, baby ! lol. It will be interesting to see what BRP brings to the table for a 4 stroke mountain sled. With all the " lightweight " problems they have encountered ( durablilty wise ). Yamaha can stand to lose a few pounds in different regions of their product, but the structure of the sled should not be compremised due to shedding weight. If Doo keeps their current clutching, 250+ hp will shred a belt in seconds. Rotax has lots of years of 4 stroke tech behind them, i'm sure they will have a strong motor, no doubt... it's the rest of the sled I wonder about.

 

[Motley Doo]

DS-650's and the older ATK 605 thumpers ran hard, no if's, and's, or but's about it! Its good for them to be stepping into the thumper issue, I'm hard core 2-strokes but I think the thumpers is where we are going to have to end up some time! Yes, the chassis is the proving point, but they have a year under their belt(no smart comments here!) with the XP platform.

 

[Ollie]

Yes, the chassis is the proving point, but they have a year under their belt(no smart comments here!) with the XP platform.

That is the point.
I personally can't stand Doo, but I have to admit, their chassis seems to be holding up fine. If the chassis can stand up to a 4 stroke then you should see a major shift in the 4 stroke market in the next couple years.

 

[Linc]

That sub 500 number is based the short track,Yamaha's is 518,Ski Doo's sled hasn't been weighed by anyone but Ski Doo and it's not in production trim,but it's going to be interesting.

 

[Mafesto]

Where did you come up with that 518#?

 

[Linc]

Yamaha site http://www.yamaha-motor.com/sport/products/modelspeccompare/558/1763/0/compare.aspx

 

[Mafesto]

Yamaha site http://www.yamaha-motor.com/sport/products/modelspeccompare/558/1763/0/compare.aspx

2009 FX Nytro MTX
553 lbs

 

[snowmanx]

2009 FX Nytro MTX
553 lbs

And aren't they actually 10-15# heavier than the listed weight?

 

[Beels]

Where did you come up with that 518#?

Short track Nytro

 

[Mafesto]

However, we are speculating the Doo being longtracked, therefore comparing to a long track nytro seems sensible.

 

[BigFish BC]

2009 FX Nytro MTX
553 lbs

you guys are comparing a short track 121 to a mountain 153 thats what linc is saying

 

[BigFish BC]

And aren't they actually 10-15# heavier than the listed weight?

no

 

[Mafesto]

you guys are comparing a short track 121 to a mountain 153 thats what linc is saying

I realize the Doo will gain some weight with a longer track.
I guess I thought that would go without saying?

 

[Linc]

I guarantee,Ski Doo will be picking the lightest model 121-153, what ever.Yamaha will do the same,so lets assume we go with the lightest and go from there.

 

[snowmanx]

Corrected info on ski doos 4 stroke

no

Oh right, it's not 10-15#, it's 24# heavier according to snowest's dry weight vs published weight.

I looked at the specs on the sled in snowest again.

It's actually the 4-TEC, 1170cc(they are calling it a 1200), inline 3 cylinder, duel overhead cams, finger followers and electronic fuel injection.

They are using magnesium (36% lighter than aluminum) and polymide (60% lighter than aluminum) in the engine.

The chassis is called the REV XR.

Sounds promising, but yes, reliability may be the key.

 

[Climbmax]

And a single throttle body.....happy boosting.

 

[89sandman]

who gets exited about a 130 hp sled? yami guys? i'd be watching ac to be the first production turbo mountain sled next year. with the new twin spar chassis and around 170 hp with 9 psi of boost. now that sounds like something to be exited about. with ac's experience with production turbo sleds it should rock and be reliable out of the box. can brp say that...

 

[snowmanx]

And a single throttle body.....happy boosting.

Must be a bad thing??

Sorry, I know nothing about 4 strokes.

 

[Goin For Snow]

Must be a bad thing??

Sorry, I know nothing about 4 strokes.

i am guessing you can't push as much PSI thru a single throttle body as well as 3 or 4.

 

[Lunch_Box]

i am guessing you can't push as much PSI thru a single throttle body as well as 3 or 4.

People have no problems pushing big boost through one throttle body in the automotive world. Depending on how big it is it might become a restiction and need to be upgraded and same goes for the intake manifold.