The O-200 gets a bad rap for carb ice, which I think is undeserved. Though I have had carb ice in them, it has been no worse than any other engine type. In conditions which are conducive, I'll use carb heat. Otherwise, I never touch it. Carb ice is not a reason for an engine to go from full power to no power suddenly. And, if you have managed to actually get the engine to quit because of carb ice, start looking for a place for a forced landing, 'cause it's too late for carb heat to do any good!
The ice which has caused me instant full engine failures (twice on O-200, and once on O-470) was ice crystals in the gas, because I had not used alcohol in the fuel to dissolve them out. That is just totally random, though an application of full power increases the odds.
The fuel quantity problem is really the focal point of a sudden engine failure in a 150, they are otherwise pretty well bullet proof. I noted the remark of "incorrect dipstick". With due respect, if it is long enough to touch the bottom of the tank, while still emerging from the top, it's the right dipstick. I am not aware of any formally approved dipstick, or marked dimensions for one for any Cessna (other type do have them). So if you're relying on markings of unapproved origin on a home made dipstick, you're playing with fire. I have seen commercially available after market ones for Cessnas, an my experience has been that if you are using the one made for the aircraft model and tank configuration, they are pretty good, but they are still not "approved", leaving the user of the dipstick responsible for the determination of quantity.
If you have anything stuck into the tank, which will touch bottom, and show a wet mark, good for you. Put your thumb and fore finger at the place where it enters the tank filler, and pull it out. If the wet spot is less than a quarter of that distance, buy some fuel before you fly, and buy more accordingly for your planned flight. Anything more complicated than that may be leading you down the garden path, and to a forced landing....