My 1973 710M sat for roughly a month until I went to fire it up and found it only wanted to run on two cylinders. After a little diagnostic work, I figured out that the rear two cylinders weren't firing, which obviously leads you to the carburetor. It turns out the float was drowned, so the carb was just dumping fuel into the cylinders. I swapped in one of my spare floats and it ran beautifully....
...except after a couple minutes it started blowing blue smoke out the tailpipe.

So, before I pull that cylinder head off, is there anything I should know or be on the lookout for?