Kitty Cat Snowmobiles

I have a 1972 Kitty with T5A Kawasaki engine. Trying to get it running for my 3 nieces. Chassis is in great condition but sled has been sitting in an enclosed room in the barn for about 30 years. Fuel was not drained, and no preservative oil was squirted into the spark plug opening when sled was put in storage.

Main problem is that recoil starter won't pull. I assume piston rings are rusted in place. Would it be a mistake to spray some WD-40 in the spark plug opening, let it sit for a few days, and if still stuck, maybe give the top of the piston a gentle tap with a wooden dowel through the spark plug opening? Or might that cause additional problems such as breaking the rings or scoring the cylinder? If the rings are rusted, does that mean they're not salvageable, or can they be loosened up? Looks like these rings (p/n 3000-484) are hard to come by. Maybe Olson Bros. or my A/C guy can rebuild the engine if that becomes necessary.

Other issues are:
1) gunk in fuel tank, which I'm trying to clean out, or will replace with new plastic tank and fuel shutoff valve. Anybody know of a good product to dissolve gunk? I've tried carb cleaner, with limited success. My A/C guy recommended paint stripper.
2) crankshaft seals probably need replaced; my local A/C guy can do that
3) needs new plug; I'll use B6HS. Is there any benefit to using a resistor plug (BR6HS)?
4) bracket (p/n 0300-859) on top of chain guard is broken
5) brake band should probably be replaced; looks like they're not available, though, so might have to replace entire brake assembly

Any ideas for this snowmobile amateur would be appreciated.

I have some t5a parts if you need them. check the parts section.

an old time remedy for that is to pure lemon oil in the cylinder let set over night and you should be able to remove the cylinder.

My brother unstuck tractor engines using (believe it or not) white vinegar. Unbelieveable how good that works.

That was prior to rebuild, though. For something to "loosen and then run", the Marvel Mystery Oil is a good choice.

KL

i've unsiezed these little engines with pb blaster and a heavy rubber bungie cord.spray the blaster in plug hole and wrap bungie tightly around flywheel so that it is pulling on it like you'd pull it with a rope to start it.let it sit for a few days.as for the fuel system id use laquer thinner because more than likely it was last ran on regular gas not todays garbage they call gas.so more than likely you have powder in fuel bowl instead of gum.