We had a great weekend on the new (?) sleds!
The Kawasaki started on the first pull when the guy dropped it off, I stopped it, started it and ran it a little bit and then I promptly pulled one spark plug wire boot off after the guy left. I jury-rigged a spark-plug setup, but I will need to find some NGK parts (hard to find in Cloquet, MN on a Saturday). It ran pretty well, but would only hit around 40-50 mph - which is perfect.
It will need work, but it's a great sled to just leave at the cabin. My rigged-up spark plug wire finally gave out, so it ran for a little while on one plug and I assume got very flooded. I got the plug wire back on, let it sit and started it up for some more running and the same thing happened. By then I got tired of pulling the starter, so I dragged it home with the other snowmobile. I can see the value of getting a smaller "vintage" snowmobile

. I will clean it up over the summer with real tools, the right parts and temperatures above 10 degrees.
The Polaris is in great shape. It is a 1983 Indy 600, but it has an Indy 400 seat and front-end. So it looks newer - almost brand-new. It started out the weekend by running great in idle, but only going about 100 feet under load. Uh-oh. I let a bunch of the old gas run out for an hour or two. The next morning, it started right up and drove all day. That is a nice sled. Not exactly "vintage", and it goes a bit too fast, but the kids were pretty careful with it. They are still too young to drive away from where I can see them. The "hose clamp governor" will be going on that sled.
My wife even drove them around a bit. I think we'll be getting her a "non-vintage" sled for next year to get her out on the trails with us and so we can go on a longer ride with all 5 of us.
I am still going to look out for a smaller old Ski-Doo, Yamaha or Artic Cat between now and next Fall. I am taking a look at those John Deeres this week as well, but I probably will not get them if anyone else is interested. He also has a matching factory John Deere trailer.
Thanks for all your help! I will post some pics.