Originally Posted by Twin-shocker
If the crank seals are not leaking or damaged in any way replacing them is pointless. Pressure testing the crankcase will show whether the seals are leaking or not, and will save time and expense which might not be required.
Contrary to popular belief carbs which have been unused for some while may need to be replaced, if very fine internal passages are blocked, and the blockages cannot be removed by something like ultrasonic cleaning.
Not going to get in a pissing match here. That being said, there are "If's" and "May's" in your advice given here. We all know that diagnostics online fall short of hands on first hand experience.
The suggestions that Scootern29, Buls4evr and I have made are based on our experience with 2 stroke motors. You bring up some good points and testing procedures, but a 40 year old TC/TS100 could use a little freshening up with new seals. If they aren't leaking when tested today, they surely will be leaking in the near future given the properties of todays gas....