430 mile power was noticeable

[shadow637]

This is EXACTLY my finding also. Really surprised me how sensitive this sled is to conditions. To this day I have not been on perfect conditions and have never hit 100mph. Stock clutching is very close and we are going to be splitting hairs like the old 2 st days to gain any mph. Over clutch it and in powder it will be a turd.

Same thing here, on groomed trails with some loose snow on top it is like I hit a wall at 90-92mph. Later that day with a little over 600 miles total on the sled I ran down a snow packed road with a little fluff for lubrication and hit 104. Still pulled the last 10mph pretty slow but it got there. Does not seem to have any where near the top end pull (70-100mph) that my Nytro had. I am sure more miles and a clutch kit will help it though. An XF7000 that a buddy has with virtually the same mileage on it behaves the same way.

 

[Studroes144]

One thing that I'd suggest to anyone experience the sled having horrible top speed it to take a marker and draw a line on the inside of the primary and secondary clutch where the belt rides. Draw a line from the center shaft straight out to the outside edge and then find a long field with decent conditions and hold it wide open as long as you can then check and see if the line is completely rubbed off. If not than it's pretty simple that the clutching is not reach it's full outshift. I did this yesterday with mine. Was running 800 feet at the most in a bare grass field because our snow melted so it certainly wasn't good conditions for top speed and I was only doing rolling starts. Seen 98 mph every time and I did 6 runs. It was still accelerating when I let off but there was a ditch at one end and woods at the other so wasn't able to hold it for too long. Checked my clutches and both marker lines were gone so both clutches completely shifted out. Put that on a hard packed trail or ice it's gonna be easily over 100 mph. Anyone experiencing this I'd say you are darn close to having your sled be very impressed just need a clutch kit to dial it in. On mine I would launch at around 15 mph, rpm jumped to 9000-9050 and hung right there every time. Only once did I see the rpm drop below 8900 but even then the sled still was accelerating hard. Got the old mans apex out and did the same run and seen 99mph on that only one time. 192 studs and same clutching setup on that as what my viper has. His apex speedo is spot on with a radar gun.

 

[davey]

I did this a couple of weeks ago, rode the sled for roughly 200 miles had lots of opportunity for wot. When i opened the cover still roughly 3/4 of marker left on the primary. Rpm is hitting 8900 so not sure what the fix is. Took it to the dealer and showed him and he is going to look into it.

 

[Studroes144]

When doing my clutching we tried two separate springs in the primary and it seemed as tho there was a sweet spot for the primary and once it was off then it's like you're saying, it was off a good 10-15mph. More than likely a different primary spring will make a big difference. The cat 7000 gained a lot by just a stiffer primary spring

 

[STAIN]

Historically, Yamaha clutches don't fully shift out from the factory. That is why they make products like the "speed sheave" Some people also cut thier clutches to get full shift out. My buddies Apex, My RX and Nytro never shifted all the way out. Maybe the Viper is different?

 

[RobWarrior]

Should I be expecting my Nytro to feel more powerful once I hit 500 miles as well?

 

[Ckondel]

Very poor top end

I have 300 miles on sled. Any clue why top end is terrible. Pinned on groomed trail 78 MPH. Couldn't even get 80. Love the ride but I'm getting terrible gas mileage with it pinned all day. I'm also still having trouble starting the sled. When it's Luke warm it doesn't want to start. Very concerned that in 0 degree weather the battery is going to die. I also have 2012 Nytro XTX back country. The Viper beats it out of the hole. At 60MPH the Nytro went by me like I was standing still.

 

[FAMILYMAN]

Re: Very poor top end

I have 300 miles on sled. Any clue why top end is terrible. Pinned on groomed trail 78 MPH. Couldn't even get 80. Love the ride but I'm getting terrible gas mileage with it pinned all day. I'm also still having trouble starting the sled. When it's Luke warm it doesn't want to start. Very concerned that in 0 degree weather the battery is going to die. I also have 2012 Nytro XTX back country. The Viper beats it out of the hole. At 60MPH the Nytro went by me like I was standing still.

Not even broke in yet.