From a quick internet search, an etec 850 motor weighs 92 pounds (42 kg). That is 20-ish pounds lighter than my viper motor. Your riding gear weighs more than that, especially if you ride with a backpack. Next, the following links post actual scale weights of both sleds without fuel which is around 65 to 70 pounds depending on tank size. Fuel roughly weighs 6 pounds per gallon. Doing simple math, that would put your sled within 25-ish pounds of my turbo viper. Your huge gap just got a little smaller.
Weight m8000 and m7000 comparisons
Uncreated my 2015 M8000 and M7000 over the weekend. Had planned to do a M8000 lite weight big bore for my project sled (money pit) this year. After weighing both sleds I'm not so sure. I really liked my 1100t, but the weight got to me enough that I ended up on a 2-stroke last year and the the...
www.snowest.com
Are the 2015 fatter than the 2013 Good info on 2013 153 @ 564lbs wet 489 dry no fuel 75lbs of fuel 2014 I have no info other than 18lbs loss on 2013 471lbs dry or 546lbs wet So I see a member weight a 162 2015 at 499lbs no fuel or even little oil In know a 162 weighs 8lbs more than a 153 but...
www.snowest.com
Also, yes my viper is an expensive sled. I never acted like it was not. It is purpose built for climbing out of the biggest chutes I can find, not simply high-marking a wide open hill. I have ridden all over the Rockies in utah, idaho, and wyoming and all the way to boulder mountain in revelstoke canada. Chute climbing is what I enjoy, and I wont apologize for that. I tree ride, what you seem to enjoy, on occasion with friends. Jumping from side to side on sidehill reversal cuts and doing re-entries is fun for a while, but it is not what I wake up to ride for. And yes, I do that on my turbo skidoo as my viper is a bit too long for tight spaces. So, my sled choices reflect my riding styles, so does your's. Like I said in my original post, 4 strokes are built for a different type of riding and they rule that arena. If you cannot understand their value, you probably don't do or like that type of riding, which is great. Do what you do.
Finally, to say a winder is not capable of tree riding is not true. The following is one of many. You can find more if you like.