Good luck with those first Jensens! It's not unusual at all to get an eBay engine that needs repairs. I've had some really good luck repairing 2 or 3 that I was REALLY disappointed in. It's a fun hobby for several reasons. They don't take up a lot of room, most will run or try to and there are lots of ways to maintain the hobby cheaply if necessary.
Enough ideas and top rate knowledge to see you through any Jensen problem.
Welcome to the room.