yamyfreak
Pro
Was out with my son yesterday. He rides a XF 7000 and I have the LTX SE. I took his for a ride and was surprised at how high the RPMs were running at. At full shift I was seeing 9200 rpm. My Viper is 8900rpm. Fuel up he took $6.00 more. Checked the belt temp and the cat was a lot hotter. I could hold my hand on the Viper clutch sheaves with no problem but on the cat I had to let go because the sheaves were that hot. I don't own a temp lazer which would have been nice to see the temp differences. Will be clutch tuning the cat. 
almond1000
Pro
- Joined
- Jan 20, 2008
- Messages
- 190
- Reaction score
- 15
- Points
- 738
- Location
- North Fond du lac, Wi.
- Country
- USA
- Snowmobile
- 2017 sidewinder 2011 vector gt 2010 fx nytro 2009 vector gt
Belt slipping? I would think getting the rpm down would help with mpg as well as clutch temps.
shadow44
TY 4 Stroke God
Cats typically over rev by 2-300 rpm, same thing happened with my F7 and all my buddies F7s....also the same thing that is happening with their 800 2strokes. I'm not sure why Cat does this cause once you get them in the right rpm range their clutching usually works very well
Sean videos of the cats revving to 9200. They need to fix that.
suburban
Expert
- Joined
- Apr 19, 2003
- Messages
- 210
- Reaction score
- 31
- Points
- 903
- Location
- ontario
- Country
- Canada
- Snowmobile
- 2021 SRX
yamyfreak said:Was out with my son yesterday. He rides a XF 7000 and I have the LTX SE. I took his for a ride and was surprised at how high the RPMs were running at. At full shift I was seeing 9200 rpm. My Viper is 8900rpm. Fuel up he took $6.00 more. Checked the belt temp and the cat was a lot hotter. I could hold my hand on the Viper clutch sheaves with no problem but on the cat I had to let go because the sheaves were that hot. I don't own a temp lazer which would have been nice to see the temp differences. Will be clutch tuning the cat.
so what happen when you ran them side by side ? 2 or 300 rpm might matter on a 2 stroke, but wouldnt be 1 hp diff on these motors.
yamyfreak
Pro
We didn't run side by side but you could tell the difference immediately. My son told me my Viper felt soooo much smother as far as clutch engagement and vibration. They are very similar in riding but he has the dual runners and I have the single. Dual is far better for darting.
yamyfreak
Pro
I have 250 miles on the Viper and he only had 50 on his. didn't want to push his with it over revving like that. The reason for no side by side racing.
wot-75
Expert
yamyfreak said:
In theory, a dual runner should increase steering effort pretty considerably as there's double the carbide to move.. Did you notice that at all? I've always been skeptical of dual runner setups...
Studroes144
TY 4 Stroke God
- Joined
- Oct 30, 2013
- Messages
- 2,897
- Reaction score
- 955
- Points
- 973
- Location
- Lowville, NY Tug hill snowmobiling
I have dual 6" runners on mine. Didn't notice any extra steering effort. Still steers super easy. They are a must with stock skis. Have done a lot of testing with my viper and an xf7000. Like u said the cat revs too high. Belt and clutch temps on the cat were a consistent 20 degrees hotter than the viper. This was with a laser temp gun. A 7000 with a clutch kit will be comparable to a totally stock viper. Add clutching to the viper and it'll be that much better. Only difference I noticed was 7000 seemed to engage a bit smoother than the viper. Could just personally feeling but it was noticeable to me.
