working on a Troy Bilt 5524 for a friend so NOT making money on it but also don't want to spend endless hours rebuilding stuff, Any how it's in decent shape except the engine (5.5hp Tecumseh) has zero compression and I am thinking a valve issue. Now my question, Will other brand 208 cc engines drop right on like the Predator 212cc. Might have a lead on one cheap and would IMHO be a decent upgrade in performance. If not it may be a predator swap but hoping I can get the 208cc winter engine for it.

if the existing is a single shaft ohv , you "should" be good to go . a few measurements would confirm before purchase.

I believe that the 208cc and Predator 212cc have exactly the same mounting bolt pattern. Both engines will be a nice upgrade in power over the original Tecumseh. The benefits of a winter engine is that you will not have to jet it richer to run correctly in cold weather. I made a shield with sheet metal to keep snow out of the governor area and hogged out the factory jet with some super floss and polish compound and it runs great even at zero Farenheit

Troy Might have a 7/8 crank.

Good catch Jack, Didn’t think to check that on the Tecumseh, now I have a lead on another Troy parts machine with a running powermore engine so may be getting that to make one good machine from the two, got to talk to the customer in the morning and see what he wants to do.