Viper glider build

[cannondale27]

This is why I haven't bought a Viper.

Its never stopped me or let me down but sure is embarrassing that they can't get this right.

 

[DGZRT]

Its never stopped me or let me down but sure is embarrassing that they can't get this right.

It has been rolling around in my head for 3 years . I know each year they have gotten better and better but when I need 2 of them then that's well over 20 k. And with the crappy winters lately I would rather put it towards a new Audi Q5 ... Besides my Vectors are setup Well ! I basically have my mind set on waiting for the new chassis and motor .

 

[DGZRT]

Enough Hi Jacking .... Grizz your mechanical and electrical skills are second to none. This Project rocks !

 

[murdered141]

Any more updates on this awesome build?

 

[grizztracks]

Working out a few minor details like the speedometer calibration but not much more going on until we get snow again. I'm hoping to get some seat time on it this winter (that's if Yamakazie will let me) and also do an on trail comparison to my 15 viper and 08 Nytro.

 

[murdered141]

I think most of us including myself are trying to figure out what is chocking our vipers.

 

[yamakazie]

Grizz and finally got the 2 Vipers together for a comparison. Sleds were not equal but but close. Grizz's "stock" Viper has some clutch work, as does mine, but he's gone a couple steps farther and the hybrid Viper still needs some minor tweaks to hit the sweat spot. He also has modified the airbox.
So, on a somewhat packed, less than a half mile stretch we lined them up on a rolling start. The Viper/Nytro hybrid, we'll call Vypro, launched to a few sled lead. At about halfway the stock Viper caught and overtook the Vypro about 4 lengths then they both were the same speed to the end of our test track. In the end stock wins but top speed was the same. We did this 3 times with similar results.
Is the Vypro starving for air on top end without the airbox mod or is it clutching? I'm sure Grizz has been racking his brain all night and will have plenty of ideas.

 

[cannondale27]

View attachment 139361 Grizz and finally got the 2 Vipers together for a comparison. Sleds were not equal but but close. Grizz's "stock" Viper has some clutch work, as does mine, but he's gone a couple steps farther and the hybrid Viper still needs some minor tweaks to hit the sweat spot. He also has modified the airbox.
So, on a somewhat packed, less than a half mile stretch we lined them up on a rolling start. The Viper/Nytro hybrid, we'll call Vypro, launched to a few sled lead. At about halfway the stock Viper caught and overtook the Vypro about 4 lengths then they both were the same speed to the end of our test track. In the end stock wins but top speed was the same. We did this 3 times with similar results.
Is the Vypro starving for air on top end without the airbox mod or is it clutching? I'm sure Grizz has been racking his brain all night and will have plenty of ideas.

The Viper/Nytro hybrid, we'll call Vypro, launched to a few sled lead

This is the only reason some think the Nytro is so much faster. Is primary clutch on your Vypro from the Nytro or Viper? I believe any other speed differences are chassis related. Now how about warm up and idle after a cold start?

 

[grizztracks]

He took me out of the hole every time and would continue to out pull me for almost 100 yards. Then it was almost as if he hit the brakes because I would rapidly make up 4 or 5 sled lengths and pass him by several sled lengths but then at top speed we'd be running about even. His clutches came off the Nyto but we are both running Schmidt bros stage II although I'm running Supertip weights. My secondary was also wrapped at 60° and I believe his was wrapped at 70° which would give mine a faster shift out making it a little sluggish on low end. His was also slightly tapping the rev limit at takeoff so he might even have a little more there with that corrected. The only way to fairly compare these two would be to put them on an engine dyno.

I really don't think the airbox mod makes that big of a difference. If there is any gain by doing that mod it's minimal and I hate the increased intake noise coming through. I believe it's the wrong approach and the proven cold air intake is the way to go. To often with these air and exhaust mods we hear about the Hp gains but for me I'm more interested in the torque numbers. I don't like giving up torque for minimal Hp gains especially for a trail sled...... Good thing the Mr Bill show isn't on this channel anymore!

The Nytro engine hasn't missed a beat on startup in the Viper chassis. My 15 Viper is getting worse. It was just an occasional problem when warm but now cold starts, regardless of temperature is giving me a problem. The starter struggles at times which is making me believe either the starter is going out or the battery is weak. I need to measure the voltage and current draw to the starter to see what's going on.

 

[grizztracks]

To much clutter in Dan's picture...........That's better

 

[cannondale27]

Schmidt Bros kit has the smaller 14.5 rollers in it right? Its probably cause I am not riding this weekend so not happy but the tunes on these are still very crappy even with latest. Yesterday mine just died for no reason. Buddy MtCooler's 7000 has done it at least twice. Once immediately after crossing a road. Now I hear about tight valves on one. Thinking that could be reason for variances. Occurred to me years ago but who wants to go into motor to check. Its going to be a long off season. Right now I hate this motor even more than first year. Yamaha needs to step up or I am out. Hopefully all the pics of the fun and this site keep me on a Yammy cause it sure has been frustrating.

 

[grizztracks]

Schmidt bro kits all have 14.7 mm rollers.... No hiccups at all with the Yamaha electronics in the Cat chassis. Makes me wish I went the same route as Dan did. He went from a 09 Nytro to a new 2015 Viper chassis at almost no cost after he parted out what was left of his Nytro.

While doing the comparison we also checked his speedometer for accuracy since I fabricated a new pickup gear with a couple more teeth. The new gear put him within a few mph of my stock Viper and after the ride he had 138 miles on his odometer compared to my 136 miles.

I kept my Nytro for a backup sled when I purchased the Viper because for the most part it has been very reliable. The Viper left me stranded once so far with a bad jackshaft bearing. I probably could have prevented that but I didn't think with only 1,500 miles it needed serviced yet. This starter stuff worries me ever time I hit the key. In fact every time I take the Viper out I always wonder what's next. On the last ride my engine got loud and I thought maybe I blew the muffler or header out but didn't find anything wrong and when I rode it a few days later it seemed normal again. I'm not sure what that's all about but maybe I should stop reading about all the problems people have had with their Vipers.

 

[cannondale27]

I hear you about the reading. Thing is it almost all eventually happens to me.

 

[grizztracks]

With all the aggravation from these sleds along with the poor winters and my recent health issues I'm seriously considering getting out of this sport. As I approach retirement it makes me wonder if I wouldn't mind spending winters in a warmer climate. A boat and a fishing pole is appealing right now.

 

[cannondale27]

With all the aggravation from these sleds along with the poor winters and my recent health issues I'm seriously considering getting out of this sport. As I approach retirement it makes me wonder if I wouldn't mind spending winters in a warmer climate. A boat and a fishing pole is appealing right now.

LOL Winter is just a beautiful time of year and works out schedule wise with work and everything else. Summer is always so busy. Really thinking a UTV will be my next purchase. But even that has this motor in it!