Stock Nytro lacking power?

no.

I don't know how much power your viper is running but the Nytro's power is much different. A lot of low end torque...

It isn't going to rip your arms off but the power is OK... after ripping around on one for a while, I was thinking of how much fun it would be with boost. the stock power isn't anything crazy by any means... don't know if that helps...

My buddy has a Viper and we ride every weekend, so I have some 1st hand knowledge of this. My Nytro is stock and his Viper has a few mods.

Drag race on the trail- Nytro totally crushes the viper, no contest.

In the powder- The viper does not seem to get on top of the snow like the nytro. Boondockin and climing you will be very pleased with a stock Nytro compaired to your Viper. Mine is only pulling 8150 rpm so I still have some clutching and gearing work to do for the 10,000 to 12,000 feet we ride at.(at 6500 feet it pulls 8900 rpm like it should) but even with the Nytro not quite dialed in, it is still no contest.

Here's 2 videos of the Nytro and Viper playin in the same field in Mancos, Colorado. The Viper goes good, but it's not as agile or as fast in the powder
as the Nyrto. The only thing the Nytro needs is a different track.

http://www.youtube.com/watch?v=QtC36dT0OvE

http://http://www.youtube.com/watch?v=Jue_yD6X2l4

Oh yeah, the Nytro only had 25 miles on it so it was not broken in yet.

To put in one perspective if you are interested in 1000foot hard pack runs. My friend who just sold his viper had about 6 go's with me a month or so ago. This Viper had Slp triples on it with a 136 x1.75 on it. Again , it's not apples to apples since my Nytro at the time had the stock 1.25 x121. But in all races the nitro was ahead and even on a roll on had more mph. Even he was impressed with the Nytro after driving it...............not enough though since he went out and bought the apex..........LOL!
I'm sure this won't be every case but the Nytro does have great torque and power , not exactly the best topend. Mine has gps 'd consistant 97 mph and has gone 98. Now with a 144 x1.75 91 consistant with a 92mph. And it will rip your arms off ..................for a couple hundred feet anyways.