edit: as always late to the rodeo. FWIW here is my original post.

Let's check against the essentials:

1) First Aid - not in your list so unless you have a dedicated kit with the snowmobile you are not mentioning add this to your kit. Even if you do have a kit with the snowmobile add at least a small FAK as there is always the possibility you will get separated from the snowmobile. Consider the possibility of broken bones and add a sam splint to the FAK as well. Also see what Hikermor said about the FAK in his post.

2) Shelter - not in your list either so add some shelter items - tent if space allows, tarp and rope, maybe the heatsheet 2.0 insulated bivvy on your person (see more about on your person items below).

3) Warmth - this category encompasses not only fire making items but extra clothing, blankets/sleeping bags, warmers, candles, etc. Ditto hikermor, add a good sleeping bag. Other good suggestions regarding ground pad too. You have some ok fire making items but I would rethink the dryer lint. Unless it has some accelerant or other additive to increase its burn time and heat output you might be surprised how ineffective it can be. I certainly was when I tried to use a small amount to start a fire from some moderately wet wood. I used my knife to get some shavings from what appeared to be the dryest parts of the wood, arranged it around the dryer lint and lit it up. The dryer lint burned up so quickly the shavings never even had a chance to ignite. Fortunately this was not an emergency situation and I have since replaced dryer lint with tinder quik tabs. If you decide to keep the lint in your kit, make sure you can start a fire with it every time; practice with some wet wood as well. I would suggest the addition of some long burning candles as well as a good lighter and some strike anywhere matches with a tinder quik in a waterproof case to be carried in a zippered pocket on your person. There are also several fire starting/fire making kit threads on the forum to look through as well. Away from fire making, add some warmers to your kit.

4) Water - See what hikermor suggested about canteen or thermos; maybe a nalgene bottle instead (wide mouth may be easier to work with). Maybe some water purification tablets too.

5) Signaling items - Hikermor has already touched on some of these. Signal mirror, plastic pealess whistle, brightly colored tarp, flagging tape, orange duct tape, rescue streamer, maybe even something to color the snow (I was thinking food coloring but surely there is something better). A brightly colored bandanna is a decent signaling aid and could also serve many other uses as well.

6) Food - what everyone else has said, high calorie, low prep (but something warm would sure hit the spot if you can fire up that stove ). Ditto extra fuel for the stove as well.

7) Tools - Good fixed blade would be ideal, multi-tool a very good idea, sharpener, flash light (no need for anything big or bulky or fancy, an LED headlamp should do nicely), extra batteries (for everything, not just the light), saw would be good but not necessary (uses a lot of energy you may want to save for other things).

8) Personal Protection and comfort - Sunscreen and sunglasses (yes even in winter; think snowblindness; also the reflection of sun off the snow can cause severe sunburns too); TP or wipes; lined work gloves; hand sanitizer; and bear spray, if that is an issue.

9) Multi-purpose and repair - repair kits for all items (tent repair, glasses repair, stove repair, etc); safety pins; sewing kit; ziploc bags of various sizes; waterproof paper and pencil; rubber bands; zip ties of various sizes; make a flat pack of your duct tape by wrapping it around a credit card or other plastic card of similar size; garbage bags; aluminum foil. Since these are all small items you may want to put them into another container so they do not get lost in the bottom of your pack.

10) Navigation - map, compass and GPS all already there so you should be good to go.

Other items: playing cards or other entertainment.

Also I would consider carrying some bare minimum items on your person in case you get separated from your pack. Check out Doug Ritter's Pocket Survival Pak ( http://www.equipped.org/psp/index.htm ), it is a good place to start and also contains many of the items mentioned above. Supplement with a good pocket size first aid kit, a good shelter item, water items (like carry bag and purification tabs), a good large bladed folding knife (or possibly the pocketknife you mentioned or the multitool we have suggested for you), small flashlight, and extra fire starting items. For the larger pack kit you should also check out Doug's 72 hour kit ( http://www.equipped.org/72hourkit.htm ) for some good suggestions (obviously some things don't apply to your situation and other items should be added to fit your needs). If the area you will be riding in has the proper materials you may be able to improvise some of these items and save some space in your kit. All goes to experience and skills. Tough to improvise though if you have a broken leg or arm. Keep that in mind too. As far as what you can eliminate, I have already mentioned what you might consider replacing. It depends on how comfortable you are with the items. I would certainly not suggest you go with something you are not experienced with vs something you have worked with for several years. That said, I would eliminate the windproof and regular matches and replace with good lighter and strike anywhere matches in a case as mentioned above. Add some of the pro force wind and waterproof matches (the ones used by the SAS). Upgrade the pocketknife to a multitool and/or larger folder. I would consider eliminating the signal laser but honestly am not familiar with its abilities. That's your call to make. It goes without saying certain items need to be kept warm and/or dry. Sorry for the lengthy post and hope this helps.